Issued 12 January 2021: Unless otherwise noted, temperature and precipitation rankings refer to a 126-year period of record (1895-2020), and long-term average refers to the 20th century (1901-2000) value. Data for 2020 should be considered preliminary. The most up-to-date temperature and precipitation data is available through Climate at a Glance.
Temperature and Precipitation Analysis
Based on preliminary analysis, the average annual temperature for the contiguous U.S. was 54.4°F, 2.4°F above the 20th century average. This ranked as the fifth-warmest year in the 126-year record. The five warmest years on record have all occurred since 2012.
Most of the contiguous U.S. experienced above-average temperatures during 2020. Ten states across the Southwest, Southeast and East Coast had their second-warmest year on record. There were no areas of below-average annual temperatures observed across the Lower 48 during 2020.
The nationally averaged maximum temperature (daytime highs) was above average for 2020 at 66.3°F, 2.3°F above average, ranking as sixth warmest in the 126-year record. Much of the western half and eastern third of the CONUS experienced above-average maximum temperatures for the year with Arizona ranking warmest on record. Portions of the lower Mississippi Valley had daytime temperatures that were below average during 2020.
The nationally averaged minimum temperature (overnight lows) during 2020 was 42.4°F, 2.4°F above average and also ranked sixth warmest in the 126-year record. Alabama, South Carolina, North Carolina, Virginia, West Virginia, Maryland and Delaware each ranked warmest on record with six additional states' minimum temperatures ranking second warmest on record.
Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand for 2020 was 31 percent of average and the 7th lowest value in the 126-year period of record.
For the year, warm daily records outpaced cold records by a margin of approximately two to one. There were over 106,000 daily temperature records tied or broken during 2020.
Influenced by warm ocean temperatures, Kahului and Hilo experienced a record-warm year in 2020.
The contiguous U.S. average annual precipitation was 30.28 inches, which is 0.34 inches above the long-term average, ranking in the middle third of the historical record.
Above-average annual precipitation was observed from the Great Lakes and Plains to the Southeast and Mid-Atlantic regions. North Carolina had its second-wettest year on record during 2020 and Virginia was third wettest. Below-average precipitation fell across much of the West, northern Plains and parts of the Northeast. Nevada and Utah ranked driest on record for 2020 with two additional western states ranking second driest. In fact, Utah's 7.23 inches of annual precipitation was 0.89 inches less than the previous record set in 1956.
According to the U.S. Drought Monitor (USDM), drought coverage expanded throughout much of 2020 with a minimum CONUS extent of 9.6 percent occurring on February 18 and maximum coverage of approximately 50 percent on December 22. Extreme (D3) and exceptional (D4) drought covered about 22 percent of the CONUS on December 29 — the largest extent of D3 and D4 drought since August 2012 (24 percent). Drought conditions expanded or intensified across much of the western U.S. and southern to central High Plains throughout 2020 with persistent above-average temperatures and precipitation deficits in place across much of the West. Much of New England experienced the emergence of drought during the second half of 2020 with marked improvement by the end of the year. Hawaii’s peak drought extent occurred during November with approximately 74 percent coverage. June and July were Puerto Rico’s most significant drought months with over 50 percent coverage; Alaska was nearly drought free during most of 2020.
Alaska Annual Summary
Despite a cold start to the year in Alaska, the statewide average annual temperature was 27.5°F, 1.5°F above the long-term average and was the coldest year since 2012. Above-average conditions were observed across much of the North Slope, West Coast and the Aleutians, primarily due to the lack of coastal sea ice. Above-average temperatures were also seen in portions of Bristol Bay, Central Interior and Northeast Interior regions. Below-average temperatures occurred across parts of the Southeast Interior region. Alaska experienced its coldest first two months of the year in 2020 and coldest winter (December 2019 - February 2020) since 1999. In October, Arctic sea ice concentration was the lowest value since the satellite records began.
Precipitation received across Alaska during 2020 varied by region with the eastern interior regions, portions of the Panhandle and Bristol Bay receiving above-average precipitation. Meanwhile, parts of northwestern Alaska, the Aleutians and the central Gulf regions received below-average precipitation for the year.
On December 31, a strong low-pressure system over the north Pacific Ocean deepened to 921 millibars (27.20 inches of mercury) as it crossed over Attu Island, the westernmost of the Aleutian Island chain. The center of low pressure for this storm is the lowest known pressure in or around Alaskan waters. The lowest known mean sea level pressure on record in Alaska was recorded on the 31st on Shemya Island at Eareckson AFB and registered at 924.8 millibars (27.31 inches of mercury). This value will be evaluated by the State Climate Extremes Committee later in 2021 to determine if a state record for lowest mean sea level pressure will be established.
Billion-Dollar Weather and Climate Disasters
- In 2020, there were 22 weather and climate disaster events with losses exceeding $1 billion each across the United States &emdash; shattering the preivous annual record of 16 events that occurred in 2011 and 2017. These events included seven tropical cyclone events, 13 severe storm events, one drought and one wildfire event.
- Annual losses in 2020 exceeded $95 billion, the fourth highest cost on record. The most costly events of the year include: Hurricane Laura, the Western wildfires and the Midwest derecho.
- Seven of the 12 landfalling storms produced at least $1 billion in damage, breaking the old record of four separate billion-dollar tropical cyclones in both 2004 and 2005.
- The Central states also experienced a historic severe weather event — the August 10 derecho — that produced damage costs of $11.0 billion. The derecho’s damage to infrastructure and crops is the third severe weather event (since 1980) with CPI-adjusted costs over $10.0 billion, joining the late-April and May 2011 tornado super outbreaks across the Southeastern and Central states.
- The total cost of U.S. billion-dollar disasters over the last five years (2016-2020) exceeds $600 billion.
- 2020 also marks the sixth consecutive year (2015-20) in which 10 or more separate billion-dollar disaster events have impacted the U.S.
Other Notable Extremes
- Through November 30, and the official end of the Atlantic hurricane season, several records were tied or broken.
- Thirty named storms formed in the Atlantic, which breaks the previous record of 28 set in 2005. The 13 hurricanes and six major hurricanes in 2020 are both the second most on record behind 2005 (15 and 7, respectively).
- Twenty-seven of the 30 named storms were the earliest named storm, for their respective number, on record.
- Twelve named U.S. storm continental landfalls occurred during 2020. This breaks the previous annual record of nine landfalls set in 1916.
- Six hurricanes made U.S. landfall, tying 1886 and 1985 for the most U.S. hurricane landfalls in a single season.
- Five named storms (Cristobal, Marco, Laura, Delta and Zeta) made landfall in Louisiana in 2020, which is the most on record for any state in one year.
- On September 14, five tropical cyclones were active at the same time in the Atlantic. This ties September 1971 for the most storms to be active at once on record.
- Category 5 Hurricane Iota formed during November and was the most intense Atlantic hurricane of the season.
- Hurricane Iota was the second-strongest November hurricane on record for the Atlantic and was the strongest Atlantic hurricane on record to occur so late in the calendar year.
- This was a record fifth consecutive year with at least one Category 5 storm in the Atlantic.
- Five Category 4 and 5 storms formed in the Atlantic during 2020, tying with 1933, 1961, 1999 and 2005 for the record.
- 2020 was the most active wildfire year on record (1983 to present) across the West. Nearly 10.3 million acres were consumed during 2020, exceeding the 2000-2010 average by 51 percent. This was the largest acreage consumed in the U.S. since at least 2000.
- The three largest wildfires in Colorado history occurred during 2020: The Cameron Peak Fire, the East Troublesome Fire and the Pine Gulch Fire each exceeded the acreage burned by the previous record, the 2002 Hayman Fire.
- Approximately four percent of California’s nearly 100 million acres were consumed by wildfires in 2020, which is the largest wildfire season on record for the state. Five of the six largest wildfires in California history also occurred during 2020. The August Complex, SCU Lightning Complex, Creek Fire, LNU Lightning Complex and the North Complex burned nearly 2.5 million acres in all. More than 4.3 million acres were consumed across California during 2020.
- With many of these large fires burning simultaneously, heavy smoke and poor air quality impacted many of the western states and Canada over many days during September.
- Wildfire activity across Alaska was below average and consumed approximately 181,000 acres in 2020 — only 15 percent of the 2010-2019 average. Although the season was below average, it was more than the 1993 to 2020 minimum of 23,000 acres set in 2004.
- Snowfall during the 2019–2020 snow season was below average across the Sierra Nevada range, the coastal ranges, Cascades, the northern and central Plains, portions of the Great Lakes and across parts of the mid-Atlantic and Northeast. In contrast, places such as Boulder, CO, experienced its snowiest season on record with 152 inches of snow. Caribou, ME, also had significant snow during the 2019-2020 season receiving 146 inches and ranked ninth highest for any season on record.
- The 2020 tornado count was slightly below-average across the contiguous U.S. with approximately 1,200 tornadoes reported. The most notable event during the year was an outbreak of at least 140 tornadoes from Texas to Maryland during April 12-13. With 32 tornado-related fatalities reported, this was the deadliest tornado outbreak across the U.S. since April 27-30, 2014. No EF-5 tornadoes were reported during 2020. The most recent tornado classified as an EF-5 occurred in 2013.
- The U.S. Climate Extremes Index (USCEI) for 2020 was 80 percent above average and ranked as seventh highest in the 111-year record. Warm extremes in both maximum and minimum temperature across much of the U.S. in addition to wet conditions across the Southeast and dry conditions in the West contributed to this elevated USCEI value. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation, drought and landfalling tropical cyclones across the contiguous U.S.
For additional details regarding these highlights, please see the following pages:
*Temperature and precipitation values and ranks are based on preliminary data. Additional data received and processed after the release of this summary may result in small differences for annual values and ranks.
These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Climatic Data Center.
Northeast Region (Information provided by the Northeast Regional Climate Center)
- The Northeast had its third warmest year on record with an average temperature of 49.5 degrees F (9.7 degrees C), 2.2 degrees F (1.2 degrees C) above normal. Annual average temperatures for the twelve Northeast states ranged from 1.9 degrees F (1.1 degrees C) above normal in West Virginia to 2.8 degrees F (1.6 degrees C) above normal in Massachusetts and Rhode Island. 2020 ranked among the seven warmest years on record for all the states: second warmest for Connecticut, Delaware, Maryland, Massachusetts, New Jersey, and Rhode Island; third warmest for New York and Pennsylvania; fourth warmest for New Hampshire; fifth warmest for Maine and Vermont; and seventh warmest for West Virginia. 2020 was the hottest year on record for six major climate sites: Scranton and Harrisburg, Pennsylvania; Atlantic City, New Jersey; Portland, Maine; Central Park, New York; and Providence, Rhode Island. The warmth kicked off in January with Boston, Massachusetts; Providence, Rhode Island; and Bridgeport, Connecticut, having their warmest January day on record with highs near or above 70 degrees F (21 degrees C). In fact, it was the first time on record that Providence reported a high of 70 degrees F (21 degrees C) in the month of January. The coldest temperature observed during winter 2019-20 in Washington, D.C., was 22 degrees F (-6 degrees C) and at Dulles Airport was 15 degrees F (-9 degrees C), which were the warmest minimum temperatures for winter on record. Allentown, Pennsylvania, had its warmest winter on record. Portland, Maine, recorded its earliest 70 degrees F (21 degrees C) day on record on March 9. Beckley, West Virginia, recorded its hottest March day since 1896 with a high temperature of 85 degrees F (29 degrees C). Coldest highest max temperatures for April were recorded at several major climate sites including Bridgeport and Hartford, Connecticut; Boston and Worcester, Massachusetts; Newark, New Jersey; Binghamton, Islip, and Kennedy Airport, New York. In addition, for the first time on record, Newark did not reach 70 degrees F (21 degrees C) during the month of April. Similarly, several other sites including Hartford, Kennedy Airport, and LaGuardia Airport (New York) did not reach 70 degrees F (21 degrees C) in April, tying as the least number of 70 degrees F (21 degrees C) days on record for April. In early May, Binghamton, New York; Harrisburg, Pennsylvania; Kennedy Airport, New York; and LaGuardia Airport, New York recorded their coldest May temperature on record. Binghamton also tied its lowest maximum temperature for May with a high of 35 degrees F (2 degrees C). In late May, Scranton, Pennsylvania, and Burlington, Vermont, set/tied their hottest May day on record. Burlington and Caribou, Maine, also had their warmest minimum temperature for May. Hartford, Connecticut, tied its coldest June temperature on record on June 1 with a low of 37 degrees F (3 degrees C). Caribou, Maine, tied its greatest number of June nights with a low of 32 degrees F (0 degrees C) or lower on June 1 and 2. On June 10, Dulles Airport, Virginia, tied its warmest June low temperature with a low of 74 degrees F (23 degrees C). Caribou, Maine, had its hottest June on record, all-time hottest day, longest stretch of days with a high of at least 80 degrees F (27 degrees C), and greatest number of June days with a high of at least 80 degrees F (27 degrees C). In addition, Burlington, Vermont, tied its greatest number of June days with a high of at least 90 degrees F (32 degrees C). The Northeast had its hottest July since recordkeeping began with an average temperature of 73.7 degrees F (23.2 degrees C), which was 4.1 degrees F (2.3 degrees C) warmer than normal. Six of the 12 Northeast states also recorded their hottest July on record: Connecticut, Delaware, Maryland, New Hampshire, New Jersey, and Pennsylvania. This July was the all-time hottest month on record for Scranton and Harrisburg, Pennsylvania; Buffalo, Syracuse, and LaGuardia Airport, New York; Burlington, Vermont; Baltimore, Maryland; Portland, Maine; Bridgeport, Connecticut; Elkins, West Virginia; and Dulles Airport, Virginia. In addition, Baltimore, Maryland; Hartford, Connecticut; LaGuardia Airport, New York; Philadelphia and Scranton, Pennsylvania; Providence, Rhode Island; and Washington, D.C. recorded their greatest number of days with a high of at least 90 degrees F (32 degrees C) for any month on record. Buffalo, New York, recorded its hottest July temperature on record and saw eight consecutive days with a high of at least 90 degrees F (32 degrees C), its longest streak on record. Portland, Maine, recorded its hottest minimum temperature for any month since 1940 with a low of 78 degrees F (26 degrees C) on July 27. Portland, Maine, recorded six days this August with a high of at least 90 degrees F (32 degrees C), tying its August record. It was the hottest summer on record for Connecticut, Massachusetts, and Rhode Island. Nine major climate sites had their hottest summer on record: LaGuardia Airport, New York; Harrisburg and Williamsport, Pennsylvania; Burlington, Vermont; Caribou and Portland, Maine; Bridgeport and Hartford, Connecticut; and Providence, Rhode Island. Hartford, Connecticut, recorded 39 days this summer with a high of at least 90 degrees F (32 degrees C), its greatest on record for summer. Caribou and Portland, Maine, had/tied their hottest November day on record, while Burlington, Vermont, had its warmest November low temperature on record. LaGuardia Airport and Central Park, New York, recorded their warmest Novembers on record. On December 1, Caribou, Maine, recorded a high temperature of 60 degrees F (16 degrees C), its warmest winter temperature on record. On the same day, Caribou had a low temperature of 50 degrees F (10 degrees C), its warmest minimum temperature for winter on record.
- The Northeast wrapped up 2020 just barely on the dry side of normal, seeing 43.61 inches (110.77 cm) of precipitation, 98 percent of normal. Eight of the Northeast states were drier than normal while four were wetter than normal. Precipitation ranged from 87 percent of normal in Connecticut and Massachusetts to 126 percent of normal in Delaware, which had its seventh wettest year. In addition, West Virginia had its eighth wettest year while Maryland had its ninth wettest. Wilmington, Delaware; Huntington, West Virginia; and Charleston, West Virginia, set/tied their greatest number of March days with measurable precipitation. Dulles Airport, Virginia, and Erie, Pennsylvania, set or tied their greatest number of April days with measurable precipitation. Charleston, West Virginia, had its wettest May on record with 8.93 inches (226.82 mm) of precipitation and its wettest spring on record with 19.14 inches (486.16 mm) of precipitation. Caribou, Maine, received only 0.88 inches (22.35 mm) of precipitation during June, tying as the driest June on record. Newark, New Jersey, had its wettest July on record with 11.17 inches (283.72 mm) of rain. Harford, Connecticut, received only 4.42 inches (112.27 mm) of precipitation during summer, making it the site’s driest summer on record. Maine had its driest September on record.
- The U.S. Drought Monitor released on January 2, 2020, showed less than 1 percent of the Northeast, a small area in Maryland and Delaware, as abnormally dry. This dryness eased by mid-February, with the Northeast becoming free of abnormal dryness for the first time since July 2019. Abnormal dryness appeared briefly in an area from central New Jersey to southeastern Massachusetts in mid-March but eased by month’s end. Abnormal dryness was next introduced during the second half of May, this time in parts of New York and northern New England. During June, abnormal dryness expanded to include parts of every state except New Jersey and moderate drought was introduced in parts of New England and New York. The U.S. Drought Monitor released in June 25 showed 16 percent of the Northeast in a moderate drought and 26 percent was abnormally dry. The last time New York and New England experienced drought conditions was in the summer/fall of 2018. During July, the general trend across the region was worsening conditions. Severe drought was introduced in Maine and New York, while moderate drought expanded and abnormal dryness encompassed nearly half the region. The U.S. Drought Monitor released on July 30 showed 29 percent of the Northeast in a severe or moderate drought and 42 percent was abnormally dry. During August, conditions worsened in New England, with severe and moderate drought expanding and almost every part of that region experiencing some level of dryness. Conditions improved in eastern New York but worsened in western New York and the western half of Pennsylvania. The U.S. Drought Monitor released on August 27 showed 37 percent of the Northeast in a severe or moderate drought and 23 percent as abnormally dry. Conditions worsened during September, with moderate and severe drought expanding and the introduction of extreme drought in New England for the first time since February 2017. In fact, by the end of September, all of Rhode Island was in an extreme drought for the first time in the U.S. Drought Monitor’s history (since 2000). The U.S. Drought Monitor released on October 1 showed 45 percent of the Northeast in an extreme, severe, or moderate drought and 25 percent as abnormally dry. During October, beneficial rainfall improved drought conditions in portions of New England; however, drought and abnormal dryness expanded or intensified in parts of New York and Pennsylvania. The U.S. Drought Monitor released on October 29 showed 47 percent of the Northeast in an extreme, severe, or moderate drought and 24 percent as abnormally dry. Conditions generally improved in the region during November. For instance, severe drought eased everywhere except southeastern New Hampshire and coastal Maine and moderate drought eased in a large portion of New England. The U.S. Drought Monitor released on December 3 showed 21 percent of the Northeast in an extreme, severe, or moderate drought and 33 percent as abnormally dry. Wetter-than-normal weather during December helped alleviate drought and abnormally dry conditions in much of the Northeast. The U.S. Drought Monitor released on December 31 showed four percent of the Northeast in a moderate drought and 19 percent of the region as abnormally dry. These areas included portions of northern New England, New York, and Pennsylvania. There were numerous impacts from the drought across the region, particularly in New England and New York. Many waterways in drought areas across the Northeast saw below-normal streamflow during summer and the first half of fall. In fact, some waterways had daily record low flows and a few, including the Aroostook River in northern Maine, recorded all-time record-low flows. In June, dam releases were reduced in New Hampshire due to dropping lake levels, resulting in small hydropower plants no longer being able to generate power. Lower than usual streamflow on the Hudson River in New York in October led to increased sodium levels in Poughkeepsie’s water supply. Low streamflow and warm water temperatures prompted several states to take actions to protect aquatic species. Dam releases were performed in the Lamprey River watershed in New Hampshire, while a section of the Salmon River in New York was closed to fishing and Connecticut officials delayed restocking trout and salmon in the Farmington River. During summer and fall, groundwater levels were also well below normal in many drought areas. Dry wells were reported in New York and across New England, including more than 275 wells in Maine. Over 1,000 wells were affected in New Hampshire, where some well drilling contractors had a waitlist of over 100 people or a 6 to 12 week wait. Some reservoirs also experienced below-normal water levels. In October, Worcester, Massachusetts, took one of its reservoirs offline due to low water levels. Water restrictions were in place for hundreds of locations in New England, as well as some locations in New York and Pennsylvania. Farmers dealt with extremely dry conditions. For instance, in late September, topsoil and subsoil were very dry for 80 to 100 percent of Maine, New Hampshire, and Rhode Island. Pasture and rangeland conditions were rated very poor (the lowest level) for 70 to 90 percent of southern New England, while 10 percent of Pennsylvania’s corn crop was rated very poor, making it some of the worst corn condition ratings in the country. Use of irrigation was widespread; however, in some locations it was expensive or water supplies ran low or dried up. For example, irrigation and labor costs exceeded $50,000 at a Massachusetts farm and were around $30,000 at a New Hampshire farm. Dry conditions prevented farmers from planting crops, and for those that were planted, moisture stress led to slowed growth and reduced yields. Forage crop yields were reduced by up to 75 percent in Maine and New Hampshire. Due to reduced yields, farmers bought hay to feed livestock, but there were hay shortages and increased prices, with a Vermont farmer spending as much as $20,000 on feed. A few northern Maine farmers initiated the process to allow for emergency haying and grazing on conservation reserve. Some cattle farmers also thinned their herds earlier than usual. In Maine, potato yields were expected to be down by at least 20 percent and wild blueberry yields were reduced due to drought and frost. Massachusetts cranberry growers reported losses. Maple syrup production was slowed in Connecticut, with one producer expecting to lose around $60,000 in revenue. Apples were smaller than usual and yields were down in parts of New England. Thousands of Christmas tree saplings died and some mature trees dropped excessive amounts of needles or turned yellow in New England. For instance, one Rhode Island farm lost 90 percent of its saplings and another farm did not open for the holiday season. Portions of New England were designated as natural disaster areas by the U.S. Department of Agriculture, making some farmers eligible for federal assistance. Drought stress also caused leaves to change color and drop earlier than usual in parts of the Northeast. This year’s drought could reduce next year’s growth of red oak and white pine trees in New Hampshire. Lawns turned brown in parts of the Northeast. In some Maine locations, a fungal disease turned stressed grass black and dry conditions caused a fungus that kills the pupa of the browntail moth caterpillar to grow too late this year, allowing the caterpillar, which defoliates trees and causes health issues, to spread farther into central Maine. Fire risk was elevated in the region this summer and fall. Much of New England saw an unusually high number of fires or atypical fire behavior, with fires burning deeper and taking longer to extinguish. Maine had its worst year for fires in 20 years with 1,000 wildfires as of September 24. Massachusetts had more than 1,000 wildfires as of late September, with 52 fires in a nine-day period from late September to early October. The state’s fire tower network was extended due to increased fire risk. There were at least four ground fires in Vermont this year, which is atypical. Rhode Island officials noted that fires were climbing trees and were concerned that items like lawn mowers and chains could spark fires, which is a behavior more typical of western U.S. wildfires and unusual in the Northeast. Burn bans were enacted in several locations. For example, in New Hampshire, an emergency drought law banning outdoor fires near public woods was in effect for a month, and several communities and the White Mountains National Forest had burn bans. Drought conditions also dried up or reduced water supplies that some firefighters rely on to fight fires.
- While February, March, and the spring season were record-setting for their lack of snow, May featured record-setting snowfall in a few locations. Warm weather in February contributed to low snowfall totals in southern and eastern parts of the region. Twelve of the 35 major climate sites had their least snowy February on record. It was the first time in Baltimore, Maryland’s 128 years of recordkeeping that that site saw no snow during February. Eleven of the Northeast’s 35 major climate sites set or tied their record for least snowy March. In addition, it was the first time on record with no measurable snow in both February and March for Bridgeport, Connecticut; Islip and Kennedy Airport, New York; and Allentown and Harrisburg, Pennsylvania. From May 8 to 11, the polar jet stream plunged south and Arctic air spilled into the Northeast, with many areas seeing snow. Elkins, West Virginia, had its snowiest May day and snowiest month of May on record, while Concord, New Hampshire, saw measurable snow in May for the first time in over 50 years. Other sites saw only a trace, but for Islip, New York, it made May a snowier month than February. In fact, according to the National Weather Service, it was the latest occurrence of snow on record for the New York City area climate sites, which saw a trace. Almost the entire Northeast saw below-normal snowfall during spring and the snow season (October through May). Seven major climate sites including Philadelphia, Pennsylvania; Baltimore, Maryland; and Atlantic City, New Jersey, tied their record for least snowy spring (March through May). It was only the second time since 1885 that Philadelphia recorded no snowfall during spring. Allentown, Pennsylvania, and Harrisburg, Pennsylvania, had their least snowy seasons (October through May) on record. Philadelphia and Washington, D.C., saw less than an inch of snow for the season for only the third time since 1885.
- Several major storms affected the Northeast during 2020. Back-to-back storms from February 5 to 8 brought an extreme mix of weather conditions to the Northeast. A rare tornado outbreak occurred on February 7 in Maryland where five tornadoes touched down: an EF-0 and four EF-1s. This was the state’s largest winter tornado outbreak. Prior to this, there had only been four February tornadoes in Maryland between 1950 and 2019. For Cecil, Montgomery, and Carroll counties, it was the first February tornado on record. The tornadoes downed trees, destroyed outbuildings, and damaged roofs and siding of some buildings. Portions of Delaware, southeastern Pennsylvania, and New Jersey also saw damaging severe thunderstorms. To the west, West Virginia saw flood-inducing heavy rain, with the greatest totals approaching 4 inches (102 mm). There were road closures, some evacuations, and reports of water in houses. Meanwhile, northern locations received heavy snow, with the greatest totals of more than 12 inches (30 cm) in New York and northern New England. Thundersnow and snowfall rates of 2 to 3 inches (5 to 8 cm) per hour were reported in central New York, where several roads were shut down due to accidents. Some parts of New York and New England also saw 0.25 to 0.50 inches (6 to 13 mm) of ice accumulation. As the storm rapidly strengthened, it set the record for the lowest February air pressure in Hartford (based on preliminary data) and produced damaging wind gusts of up to 80 mph (36 m/s), particularly in coastal areas. The strong winds downed trees and wires, knocked out power to more than 86,000 customers in Massachusetts, and caused whiteout conditions in northern Maine. A complex storm system brought severe weather and snow to the Northeast in early April. Southern parts of the region experienced severe weather from April 7 to 9. Straight-line winds of up to 80 mph (36 m/s) caused extensive damage in several locations. For example, in western West Virginia, portions of two 180-foot (55 m) communications towers were knocked over, a building at a car dealership collapsed, and the roofs of several homes were damaged or destroyed. Storm reports also indicated that hail accumulation of several inches was plowed off roads in western West Virginia. To the north, in western Pennsylvania, three weak (EF-0 or EF-1) tornadoes damaged trees and buildings, the Pittsburgh International Airport recorded its second highest thunderstorm wind gust on record at 75 mph (34 m/s), and a hangar and plane were destroyed at the Arnold Palmer Municipal Airport. As the low-pressure system that produced the severe weather moved towards New England, a second low developed over the Gulf of Maine and rapidly strengthened to a near-record level for April for Maine. The result was strong wind gusts for the entire Northeast and a major late season snowstorm for parts of Maine and New Hampshire from April 9 to 10. The greatest storm snow totals approached 21 inches (53 cm). Caribou, Maine, recorded 10.9 inches (27.7 cm) of snow on April 10, making it the site’s second snowiest April day on record. The snow from the storm helped Caribou have its second longest streak with at least an inch (2.54 cm) of snow depth at 159 days (November 12, 2019 to April 18, 2020). The record of 163 consecutive days was set last year. The heavy, wet snow and strong winds downed trees and caused more than 266,000 customers in Maine, around a third of the state, to lose power. Coastal flooding occurred from New Jersey to Maine. A complex storm system moved across the Northeast from November 30 to December 1. Up to 5 inches (127 mm) of rain fell, with the greatest amounts in northern and eastern Maine. Flooding in southeastern Pennsylvania, Delaware, and portions of New Jersey and Maryland led to road closures, stranded vehicles, and water rescues. Severe thunderstorms in these same areas downed trees and powerlines, as well as spawned three tornadoes: an EF-1 that snapped and uprooted trees in northern Maryland, an EF-0 that destroyed several barns in northern Maryland, and an EF-0 that damaged several buildings in southeastern Pennsylvania. Non-thunderstorm wind gusts of up to 70 mph (31 m/s) were recorded in New England and on New York’s Long Island, with reports of downed trees and wires. In addition, snow fell across portions of West Virginia, western Maryland, western Pennsylvania, and western New York. The greatest totals of over 12 inches (30 cm) were reported in northwestern Pennsylvania, with a location in Erie County picking up 22.5 inches (57.2 cm). A historic snowstorm dropped snow on almost every part of the Northeast from December 16 to 17. Storm snow totals exceeded 24 inches (61 cm) in an area stretching from central Pennsylvania through New York and into northern New England, where snow fell at rates of at least 3 to 4 inches (8 to 10 cm) per hour. The highest snowfall totals of 40 to 44 inches (102 to 112 cm) were reported in central New York, eastern Vermont, and western New Hampshire. Two-day snowfall totals ranked as the largest on record for any month at Binghamton, New York, which saw 40.0 inches (101.6 cm) of snow, and Williamsport, Pennsylvania, which picked up 24.7 inches (62.7 cm). Concord, New Hampshire, saw 24.2 inches (61.5 cm) on December 17, making it the site’s all-time snowiest day on record and qualifying as the largest December snowstorm. In addition, December 17 became the snowiest December day on record for Binghamton, with 26.4 inches (67.1 cm), and Albany, New York, with 19.7 inches (50.0 cm). For several other locations in the Northeast, the storm’s daily or two-day snow total ranked among the ten greatest for December or any month on record. Portions of West Virginia and the Mid-Atlantic also saw freezing rain, with ice accumulations of up to 0.41 inches (10.41 mm), and sleet. Wind gusts of up to 62 mph (28 m/s) accompanied the storm in coastal areas, where minor to moderate flooding occurred. The storm contributed to hundreds of vehicle crashes, including a pileup involving more than 65 vehicles on Interstate 80 in central Pennsylvania. In addition, Interstate 81 near Binghamton, New York, was shut down for several hours due to disabled vehicles. Just a week later, on Christmas Eve and Christmas Day, a storm system dropped as much as 6 inches (152 mm) of rain on the region, with several locations having one of their 10 wettest December days on record. The combination of heavy rain, melting snow, and wet antecedent conditions led to flooding in central/eastern New York, the eastern half of Pennsylvania, and Delaware. Storm reports noted numerous road closures, multiple water rescues, some evacuations, and a few homes taking on water.
- Several notable widespread wind events occurred in the Northeast this year. From April 12 to 13, a storm system produced damaging winds in the Northeast. Non-thunderstorm wind gusts of 40 to 60 mph (18 to 27 m/s) were common, with some of the highest wind gusts reaching 82 mph (37 m/s) near Lanoka Harbor, New Jersey; 80 mph (36 m/s) in Milton, Massachusetts; 79 mph (35 m/s) in Dewey Beach and Indian Beach, Delaware; and 75 mph (34 m/s) in Moosic, Pennsylvania. Across the region, the strong winds downed trees and wires and damaged homes and buildings. For instance, a roof was blown off a store in Cape May, New Jersey, and a cow barn was tossed into a power pole in Rockland, Massachusetts. Hundreds of thousands of customers lost power in the Northeast, including more than 115,000 customers in Massachusetts. In addition, two weak (EF-0 or EF-1) tornadoes snapped trees and damaged houses in northern Maryland. On June 3, a line of intense thunderstorms with wind gusts of up to 93 mph (42 m/s) raced across Pennsylvania and New Jersey. The event, which qualified as a derecho, caused widespread damage, downing trees and wires, knocking out power to more than 500,000 customers, and causing four deaths. There were more than 250 wind damage reports in the Philadelphia/Mt. Holly National Weather Service forecast area. On October 7, a derecho produced a 320-mile (515 km) long path of damage from central New York to eastern New England. Winds gusted to 82 mph (37 m/s), with locally higher gusts of up to 100 mph (45 m/s) in eastern New York. The Albany International Airport in New York recorded a wind gust of 67 mph (30 m/s), its highest October wind gust since 1987. In addition, there were two EF-0 tornadoes, one in eastern New York and one in eastern Massachusetts. Numerous trees and branches were felled due to a combination of strong winds, drought stress, and being fully leafed. There were more than 120 wind damage reports in western New England and eastern New York, where there were two storm-related fatalities. In addition, almost 400,000 customers lost power. Another widespread wind event occurred on November 15. Wind gusts of 40 mph (18 m/s) to 80 mph (36 m/s) damaged buildings and downed trees and wires, leading to power outages. More than 185,000 customers lost power in Pennsylvania. The winds caused water levels to rise significantly along Lake Erie’s eastern shoreline, resulting in flooding near Erie, Pennsylvania, and Buffalo, New York.
- Several tropical systems affected the Northeast this year, with Tropical Storm Fay, Tropical Storm Isaias, and Tropical Storm Zeta being particularly noteworthy. Tropical Storm Fay formed on July 9, becoming the earliest “F” named storm. Fay made landfall near Atlantic City, New Jersey, on July 10 and dropped between 3 and 7 inches (76 to 178 mm) of rain on parts of Maryland, Delaware, eastern Pennsylvania, New Jersey, southeastern New York, and southwestern Connecticut. In fact, Philadelphia, Pennsylvania, had its fourth wettest July day on record with 4.15 inches (105.41 mm) of rain on July 10. On the northern side of the city, Frankford Creek reached moderate flood stage for the second time in a week. Flash flooding was reported from Delaware to New York, resulting in road closures and water rescues. The storm’s winds also downed trees and power lines. In addition, there was one fatality in Margate City, New Jersey, due to a rip current. The remnants of Fay helped spawn an EF-0 tornado in southern Maine on July 11. The tornado, the first of the year in New England, snapped and uprooted trees. Tropical Storm Isaias, the Atlantic Ocean’s earliest "I" named tropical system on record, produced extreme rainfall, tornadoes, and damaging winds in the Northeast on August 4. The greatest rain totals ranged from 4 to 9 inches (102 to 229 mm), with Allentown, Pennsylvania, having its wettest August day with 4.92 inches (124.97 mm) of rain. Significant flooding occurred, particularly in southeastern Pennsylvania where several waterways recorded their highest water levels on record. For instance, the Perkiomen Creek at Graterford, Pennsylvania, reached 19.14 feet (5.83 m), nearly a foot (0.30 m) higher than its previous record from 1935. Across the region, there were hundreds of closed roads, stranded vehicles, water rescues, and buildings affected by flooding. Preliminary estimates indicated millions of dollars in damage from flooding along the Schuylkill River near Philadelphia, Pennsylvania. Isaias produced 17 tornadoes in the region (10 in Maryland, three in Delaware, two each in Pennsylvania and New Jersey, and one in Connecticut), with the strongest rated EF-2. One tornado in Delaware was on the ground for over 35 miles (56 km), the state's longest tornado track on record. The storm's highest wind gusts ranged from 60 to 78 mph (27 to 35 m/s). Mount Washington, New Hampshire, had its highest August wind gust of 147 mph (66 m/s). The tornadoes and wind gusts caused structural damage and downed numerous trees. More than 2.5 million customers lost power, making it one of the largest storm-related outages for two energy companies. Power outages lasted five days in some locations. There were at least five storm-related deaths. Preliminary damage estimates in Delaware exceeded $20 million. Tropical Storm Zeta and another storm system trekked through the Mid-Atlantic, bringing rain, snow, and gusty winds to the region from October 29 to 30. Rainfall totals were generally less than 3 inches (8 cm), with higher amounts in northern West Virginia, south-central Pennsylvania, and central and southern Maryland. Flooding led to road closures in portions of Maryland and Delaware. Snow fell across portions of New England, New York, northern Pennsylvania, and northern New Jersey, with the greatest snowfall totals at least 6 inches (15 cm) in central and eastern Massachusetts. With 4.3 inches (10.92 cm) of snow, Boston, Massachusetts, had its snowiest October (old record was 1.1 inches [2.8 cm] in 2005) and snowiest October day on record. Providence, Rhode Island, picked up 1.6 inches (4.1 cm) of snow on October 30, tying as the site’s snowiest October day on record. Several other locations had one of the five snowiest Octobers on record. Some branches and wires were downed in parts of Massachusetts due to snowfall and/or gusty winds. Wind gusts of up to 50 mph (22 m/s) were recorded in several coastal locations of Maryland, Delaware, and New Jersey, where some coastal flooding occurred.
- There were several flash flooding events during the year. One particularly notable event was severe flash flooding in the northern suburbs of Philadelphia, Pennsylvania, on July 6. Between 3 and 6 inches (76 to 152 mm) of rain fell in a two-hour period at rainfall rates of 3 or more inches (76 mm) per hour. This led to rapid rises and moderate flooding on some waterways. For instance, the Frankford Creek rose 4 feet (1 m) in 10 minutes, while Pennypack Creek reached 10.45 feet (3.19 m), which ranked as the ninth highest water level since 1965 (based on preliminary data). There were numerous closed roads, submerged vehicles, and dozens of water rescues. A rare flash flood emergency was issued by the Philadelphia/Mt. Holly National Weather Service office. Parts of New Jersey also experienced heavy rain and flash flooding, with reports of water up to car hoods in Ocean City. On August 7, just a few days after Isaias' excessive rainfall, strong storms produced heavy rain and more flash flooding in southeastern parts of the region. Winterthur, Delaware, saw 4.11 inches of rain (104.39 mm), more than a month's worth, in an hour, with 1.03 inches (26.16 mm) of that falling in five minutes, qualifying as a 1,000-year storm event. Northern Delaware experienced some of its worst flash flooding in at least 15 years. In southeastern Pennsylvania, Chester Creek rose to its fourth highest water level on record, exceeding its previous fourth highest level set days earlier. Flash flooding due to heavy rain occurred again in parts of Maryland, Delaware, southeastern Pennsylvania, and New Jersey on August 12 and 13. There were road closures, cars trapped in floodwaters, and water rescues. Quick rises on waterways were observed. For instance, in Maryland, East Branch Herbert Run at Arbutus rose more than seven feet (2 m) in an hour and the Patapsco River at Elkridge rose 9.6 feet (2.9 m) in over an hour. As much as 5 inches (127 mm) of rain fell in a two-hour period on September 10, leading to flash flooding in Washington, D.C., and surrounding suburbs. There were numerous road closures and several water rescues. A stream gauge near Colesville, Maryland, rose eight feet (2.4 m) in around an hour. Highly-localized flooding was also noted on western Long Island and in northeastern Massachusetts. On the same day, Atlantic City, New Jersey, saw 3.97 inches (100.84 mm) of rain, making it the site’s wettest September day on record. The old record was 3.86 inches (98.04 mm) of precipitation on September 14, 1973.
- For more information, please go to the Northeast Regional Climate Center Home Page.
Midwest Region (Information provided by the Midwest Regional Climate Center)
- Annual precipitation averaged across the Midwest was 37.72 inches (958 mm), 0.78 inches (20 mm) above normal. This was the eighth straight year above the 1981-2010 normal for the region. This ranked as the 37th wettest in history since 1895. Kentucky was the wettest state with 9.97 inches (253 mm) above normal which ranked as the 8th wettest in its history. Three more states had more than 2.00 inches (51 mm) above normal and another two (Illinois and Wisconsin) had more than 1.00 inch (25 mm) above normal. Indiana was barely below normal (-0.04 inches or -1 mm), while Minnesota (-3.75 inches or -95 mm) and Iowa (-5.84 inches or -148 mm) were well below normal. Iowa ranked as the 30th driest in its history. Wisconsin, like the region, has recorded eight straight years above normal. The six Midwest states with above-normal precipitation in 2020 all exceeded their normal annual precipitation by November, and Kentucky did so in October. Iowa had its 3rd driest August in history.
- Temperatures across the region for 2020 averaged 1.2 degrees F (0.7 C) above normal. This ranked 2020 as the 12th warmest since 1895, and the warmest year since 2012. All nine Midwest states were above their 1981-2010 normal by 0.9 to 1.8 degrees F (0.5 to 1.0 C). Ohio ranked as the 7th warmest in its history and Michigan ranked 10th. The seven other states ranked between 13th and 26th in their respective histories. Four states (Indiana, Kentucky, Missouri, and Ohio) have had six straight years above normal while the other five states, and the region as a whole, were below normal in 2019. January (9th) and November (7th) were months that ranked among the top-10 warmest for the region while October ranked as the 13th coolest in history. June, July, and December also ranked among the warmest 20 percent (top 25) of history for the region.
- The Midwest was completely free of drought from January through May of 2020. That 21-week stretch extended to a 29-week stretch when the last eight weeks of 2019 were added making it the second longest stretch with no drought in the region since 2000. The only streak longer was during the first 32 weeks of 2019. A streak of 14 straight weeks, from mid-January to mid-April, set a new record with no abnormally dry area in the region. This topped the 12-week stretch in early 2019 with no abnormally dry conditions. Moderate drought first emerged in Minnesota in early June and by the end of July had touched parts of all nine Midwest states. Severe drought touched parts of the five western-most states and extreme drought affected parts of southwestern Missouri and western Iowa. Parts of northwestern Iowa remained in extreme drought as the year came to an end.
- Severe weather in the region was spread across many months, however the most newsworthy was a severe derecho on August 10th. Damage was spread across Iowa, Wisconsin, Illinois, Michigan, and Indiana. The highest winds, over 100 miles per hour (161 km per hour), were in central Iowa causing severe damage to crops and trees. Millions of acres of crops were flattened by the storm. As the derecho headed east the winds eased slightly but continued to do significant damage in the other states affected. Power outages affected millions in the region with many outages lasting days or even weeks in some cases. There were at least 60 injuries and 4 deaths attributed to the storm system. Two other costly severe weather outbreaks in the Ohio River Valley included one on March 27th-28th and a severe hail storm on April 7th-8th.
- Flooding and flash flooding caused fatalities in the Midwest. March 20th saw six flooding deaths in Indiana when bridges were washed out near Laurel, Indiana. Flooding issues were noted especially in eastern Kentucky in February, the Ohio River flood plain in the spring but also along the Mississippi River system. In May, a Midland, Michigan dam failed due to heavy rains over three days, 17th-19th. More than 10,000 residents of Midland were evacuated in less than 12 hours with no loss of life.
- Corn and soybean crops in the Midwest had favorable conditions in 2020 except for the areas hit by drought and the derecho. Several Midwest states had record yields for corn and/or soybeans. Corn yields were new records in Minnesota, Wisconsin, Indiana, and Kentucky. Soybean yields set records in both Indiana and Kentucky. Crops largely reached maturity and were harvested after drying down in the field. The lack of a need for supplemental drying was a benefit for farmers. Yield losses in Iowa were due to a combination of drought and damages from the derecho. Good harvest conditions in Iowa limited the loss from the derecho and lodged crops.
- The remnants of Hurricane Cristobal moved across the region June 8th-10th. The path taken by the storm system was one of the furthest to the west and north in history. The center of the system moved across Iowa as just the second tropical system to do so. It was also just the third to make it as far north as Wisconsin.
- Spring freeze damage was reported in a mid-April freeze despite not being particularly late in the season. An early season freeze event occurred in the Upper Midwest on September 8th-11th. The rapid drop in temperatures, from warm conditions just prior to the freeze, exacerbated the situation.
- For further details on the weather and climate events in the Midwest, see the weekly and monthly summaries in the Midwest Climate Watch page.
Southeast Region (Information provided by the Southeast Regional Climate Center)
- Temperatures were well above average across much of the Southeast during the year, particularly in Florida and along coastal portions of the region. Annual mean temperatures were at least 2 degrees F (1.1 degrees C) above average for approximately 52 percent of the 168 long-term (i.e., period of record equaling or exceeding 50 years) stations across the region. Over 45 percent (77 of 168) of the long-term stations observed annual mean temperatures that were within their five warmest values on record. At least five of these stations were located in every state, including many of the major cities within the region. Sixteen of the long-term stations observed or tied their warmest annual mean temperature on record, including Miami, FL (1895–2020; 79.3 degrees F, 26.3 degrees C), Tampa, FL (1890–2020; 76.3 degrees F, 24.6 degrees C), Savannah, GA (1874–2020; 70.4 degrees F, 21.3 degrees C), Cape Hatteras, NC (1893–2020; 66.8 degrees F, 19.3 degrees C), and Norfolk, VA (1874–2020; 64.0 degrees F, 17.8 degrees C). The extreme departures in annual mean temperatures across the region were driven primarily by exceptionally warm daily minimum temperatures, as a persistent influx of tropical moisture and cloud cover suppressed nighttime cooling during the year. While 25 long-term stations observed average daily maximum temperatures that were ranked within their five warmest values on record, more than four times the number of stations (102) observed average daily minimum temperatures that were ranked within their five warmest values on record. The persistence of nighttime warmth was exceptional for many locations across the region, particularly in Florida. Numerous long-term stations observed their highest or second highest annual count of days with a minimum temperature at or above 70 degrees F (21.1 degrees C), including West Palm Beach, FL (1888–2020; 261 days, 71 percent of the year), Orlando, FL (1892–2020; 177 days, 48 percent of the year), Lumberton, NC (1903–2020; 87 days, 24 percent of the year), and Roanoke, VA (1912–2020; 45 days, 12 percent of the year). In addition, several stations observed their highest or second highest annual count of days with a minimum temperature at or above 75 degrees F (23.9 degrees C), including Fort Lauderdale, FL (1912–2020; 186 days, 51 percent of the year), Sarasota-Bradenton, FL (1911–2020; 132 days, 36 percent of the year), Vero Beach, FL (1942–2020; 98 days, 27 percent of the year), and Albany, GA (1892–2020; 44 days, 12 percent of the year). Average daily maximum temperatures were well above average along coastal portions of the region. In Florida, West Palm Beach, Jacksonville (1871–2020), and Pensacola (1879–2020) observed their highest or second highest annual count of 313, 238, and 208 days with a maximum temperature at or above 80 degrees F (26.7 degrees C). Several notable maximum and minimum temperature records occurred across the region during the year. On June 26th, Tampa, FL tied its warmest daily maximum temperature for any month on record, at 99 degrees F (37.2 degrees C). From July 19th through the 22nd, Norfolk, VA observed its longest streak of 4 consecutive days with a maximum temperature of at least 100 degrees F (37.8 degrees C). On November 11th and 12th, a total of 56 long-term stations across the region observed their highest daily minimum temperature on record for November, including Tampa, FL (78 degrees F, 25.6 degrees C), Savannah, GA (76 degrees F, 24.4 degrees C), Charleston, SC (1938–2020; 74 degrees F, 23.3 degrees C), Charlotte, NC (1878–2020; 70 degrees F), and Charlottesville, VA (1893–2020; 66 degrees F, 18.9 degrees C). Many locations across the region observed their coldest Christmas Day in at least two decades. With a daily maximum temperature of 24 degrees F (-4.4 degrees C), Asheville, NC (1876–2020) recorded its coldest Christmas Day since 1983, while Huntsville, AL (1907–2020) observed its coldest Christmas Day since 1985, with a daily maximum temperature of 32 degrees F (0 degrees C). With a daily maximum temperature of 35 degrees F (1.7 degrees C), Atlanta, GA (1878–2020) recorded its coldest Christmas Day since 1989, while Orlando, FL (1892–2020) observed its coldest Christmas Day since 1995, with a daily maximum temperature of 53 degrees F (11.7 degrees C). Dropping to 16 degrees F (-8.9 degrees C) on December 26th, Greensboro, NC (1903–2020) ended its longest streak of 694 consecutive days with a daily minimum temperature at or above 20 degrees F (-6.7 degrees C), surpassing the previous record by 277 days. The coldest temperature observed during the year was -4 degrees F (-20 degrees C), which was recorded on Mt. Mitchell, NC on December 26th. The warmest temperature observed during the year was 102 degrees F (38.9 degrees C), which was recorded at several locations across the region, including Macon, GA (July 20th), Athens, GA (July 20th), and Norfolk, VA (July 19th, 21st, and 28th).
- Annual precipitation totals were well above average across the Southeast region, with widespread areas of exceptional wetness occurring in every state and Puerto Rico. Indeed, nearly the entire Southeast region was covered with above-average annual precipitation totals, except for a few small pockets of unusual dryness in southwestern Alabama, the Big Bend region of Florida, Puerto Rico, and the U.S. Virgin Islands. The lowest annual precipitation total for any station (excluding CoCoRaHS) across the region was recorded in East Hill on St. Croix, USVI, which observed only 35.69 inches (907 mm) of precipitation. The wettest locations were found across much of Virginia, the Carolinas, Alabama, northern and central Georgia, the western half of the Florida Panhandle, southeastern Florida, and Puerto Rico. Annual precipitation totals ranged from 12 to more than 20 inches (305 to more than 508 mm) above average in these areas. Approximately 64 percent of the 168 long-term stations across the region observed annual precipitation totals that were at least 12 inches above average. A total of 85 long-term stations across the region, with at least five located in every state, observed annual precipitation totals that were ranked within their five highest values on record. Of these 85 stations, twenty-five observed their wettest year on record, including Highlands, NC (1879–2020; 136.50 inches, 3,467 mm), Fort Lauderdale, FL (1912–2020; 104.00 inches, 2,642 mm), Scottsboro, AL (1891–2020; 86.69 inches, 2,202 mm), and Lynchburg, VA (1893–2020; 69.73 inches, 1,771 mm). All but three of these 25 stations were located in North Carolina and Virginia. The highest annual precipitation total for any station (excluding CoCoRaHS) across the region was recorded in Highlands, which surpassed its previous wettest year on record (2018) by 11.04 inches (280 mm). In addition, Highlands was only 3.44 inches (87 mm) short of exceeding the highest annual precipitation total ever recorded in North Carolina, which occurred just two years ago on Mt. Mitchell (139.94 inches, 3,554 mm). Asheville, NC (1869–2020) observed its highest annual count of 157 days with measurable precipitation, while Miami, FL (1895–2020) tied its highest annual count of 30 days with at least 1 inch (25 mm) of precipitation. Numerous daily precipitation extremes were recorded across the region during the year. On February 6th, a slow-moving low pressure system produced over 5 inches (127 mm) of rainfall across portions of western North Carolina and Upstate South Carolina. Greenville-Spartanburg, SC (1884–2020) and Hickory, NC (1949–2020) observed their wettest February day on record, with 5.36 and 5.31 inches (136 and 135 mm) of precipitation, respectively. From April 19th through the 20th, a line of thunderstorms produced heavy rainfall across central portions of Alabama and Georgia, with 24-hour precipitation totals exceeding 5 inches and numerous reports of localized flooding. On the 20th, Clanton, AL (1893–2020) reported 8.40 inches (213 mm) of rainfall, which ranked as its second wettest April day on record. In addition, Columbus, GA (1891–2020) and Macon, GA (1892–2020) observed their wettest and second wettest April day on record, with 5.92 and 4.41 inches (150 and 112 mm) of rainfall, respectively. From May 19th through the 21st, a slow-moving upper-level low ushered in a deep stream of moisture across the western Carolinas and southwestern Virginia, with 72-hour precipitation totals exceeding 8 inches (203 mm) and numerous reports of localized flooding. Roanoke, VA (1912–2020) reported 8.32 inches (211 mm) of rainfall during this event, which is its fourth wettest 3-day rainfall total for any month on record. Roanoke also observed its longest streak of 3 consecutive days with at least 2 inches (51 mm) of precipitation. The Roanoke River crested almost 6 feet (1.8 meters) above flood stage on May 21st, sending water rushing onto some roadways and making them impassable. On August 31st, a line of slow-moving thunderstorms brought over 5 inches of rainfall to Johnston County, NC, where a 5-year-old girl and her 4-year-old brother were swept away in floodwater. Annual snowfall accumulations were below average across much of the Southeast region, particularly in the higher elevations of North Carolina and Virginia. Washington, D.C. (1884–2020), Blacksburg, VA (1893–2020), and Mt. Mitchell, NC (1925–2020) recorded 0.2, 10.2, and 64.2 inches (5, 259, and 1,631 mm) of snowfall during the year, which is 17.9, 12.5, and 13.2 inches (455, 318, and 335 mm) below their long-term averages, respectively. Washington, D.C. observed its lowest annual snowfall total since records began in 1884, while Washington Dulles International Airport, VA observed its third lowest annual snowfall total (4.7 inches, 119 mm) since records began in 1962. On January 31st, Charlotte, NC continued its record of reporting at least a trace of snow in every winter season since 1878. On December 16th, a winter storm produced freezing rain, sleet, and snow across portions of North Carolina, Virginia, and Washington, D.C. Freezing rain accumulations of 0.05 to as much as half of an inch (1 to as much as 13 mm) occurred in central and western portions of North Carolina, as well as southwestern, central, and northern parts of Virginia. Snowfall totals of 2 to more than 8 inches were found across portions of northern Virginia, with the greatest accumulation of 11.5 inches (292 mm) measured in Bayse, VA. About 200 vehicle crashes and 125 disabled vehicles were reported by the Virginia State Police along I-81 and across northern Virginia. In addition, about 36,000 homes and businesses in Virginia were without power following the height of the storm. Early on December 25th, snow flurries were reported as far south as Charleston International Airport, SC, which is only its second trace of snowfall on Christmas Day since 1938. In addition, Augusta, GA (1871–2020) observed only its second trace of snowfall on Christmas Day since records began 149 years ago. With 1.1 inches (28 mm) of snow on the 25th, Asheville, NC (1869–2020) observed its fifth highest snowfall on Christmas Day since records began 151 years ago.
- Thirteen tropical cyclones (Tropical Storm Arthur, Tropical Storm Bertha, Tropical Storm Cristobal, Tropical Storm Fay, Hurricane Isaias, Tropical Storm Kyle, Hurricane Laura, Hurricane Marco, Hurricane Sally, Tropical Storm Beta, Hurricane Delta, Hurricane Zeta, and Tropical Storm Eta) brought high winds, heavy rainfall, inland flooding, storm surge, and tornadoes to widespread portions of the Southeast region, including Puerto Rico and the U.S. Virgin Islands. The precursor disturbance to Tropical Storm Bertha caused a significant multi-day rainfall event across southern Florida, with accumulations of more than 8 inches in several locations. On May 26th, Miami, FL observed a 24-hour rainfall total of 7.40 inches (188 mm), which is its third wettest May day on record. From July 29th through the 30th, Tropical Storm Isaias impacted parts of Puerto Rico, with over 9 inches (229 mm) of rainfall recorded in Juncos. On the 30th, San Juan (1898–2020) observed its second wettest July day on record, with 4.46 inches (113 mm) of precipitation. Numerous fallen trees, mudslides, and river flooding were reported in southwestern Puerto Rico, according to local emergency management officials. Strengthening to a hurricane, Isaias made landfall near Ocean Isle Beach, NC on August 3rd, with peak sustained winds of 85 mph (38 m/s) and a maximum wind gust of 99 mph (44 m/s) in Federal Point, NC. The 8.5–9.5 feet (2.6–2.9 meters) of storm surge destroyed many sand dunes and sea turtle nests in Oak Island, NC. A total of 22 tornadoes were spawned by Isaias, including a rare EF-3 tornado that caused 2 fatalities and 14 injuries in Bertie County, NC on August 4th. Hurricane Sally made landfall near Gulf Shores, AL on September 16th, with peak sustained winds of 105 mph (47 m/s) and a maximum wind gust of 121 mph (54 m/s) reported at Fort Morgan, AL. However, from the 12th through the 16th, Sally impacted parts of Florida with numerous reports of localized flooding, resulting in several road closures, stalled vehicles, and water entering multiple residences and businesses. Key West, FL (1871–2020) received 9.37 inches (238 mm) of rainfall from the storm on the 12th, which is its fifth wettest day for any month on record. Of this 24-hour precipitation total, Key West observed 3.95 inches (100 mm) in a single hour, which is its second highest hourly rain rate ever recorded. On the 16th, Pensacola, FL observed its fourth wettest day for any month on record, with 11.85 inches (301 mm) of rainfall. In addition, storm surge flooding reached 5.6 feet (1.7 meters) in Pensacola, which is the third highest storm surge ever recorded in the city. There were 8 fatalities attributed to Hurricane Sally, including a 45-year-old female kayaker who had gone missing at the height of the storm. After making landfall near Creole, LA on October 9th, the remnants of Hurricane Delta impacted parts of the Southeast with heavy rain and flooding. Atlanta, GA (1878–2020) received 4.55 inches (116 mm) of rainfall from Delta on the 10th, making it the second wettest October day on record. A total of 13 tornadoes were spawned by Delta, including an EF-1 tornado that injured 2 people at a homeless shelter in Newton County, GA on October 10th. Hurricane Zeta made landfall near Cocodrie, LA on October 28th, with a wind gust of 91 mph (41 m/s) reported in Mobile, AL. Farther inland, winds gusted over 50 mph (22 m/s) in northern Georgia, Upstate South Carolina, and North Carolina, resulting in widespread downed trees and power outages. There were 8 fatalities from Hurricane Zeta, including in Acworth, GA where a large oak tree was uprooted and fell onto a mobile home, killing a man. From November 8th through the 12th, Tropical Storm Eta produced 5 to more than 10 inches (127 to more than 254 mm) of rainfall across portions of west-central and southern Florida. On the 9th, Fort Lauderdale, FL observed its third wettest November day on record, with 7.30 inches (185 mm) of precipitation. On the 11th, Sarasota-Bradenton, FL (1911–2020) observed its wettest November day on record, with 6.41 inches (163 mm) of rainfall. Numerous roads in the urbanized corridor of southeastern Florida became impassable due to flooding, with many reports of stalled or submerged vehicles. In Pinellas County, FL, sheriff deputies rescued 33 people from flooded homes and stalled vehicles. A man in Bradenton Beach, FL was electrocuted when he touched an appliance while standing in floodwater. On November 11th and 12th, the interaction of moisture surging northward from Tropical Storm Eta and an approaching cold front produced 3 to more than 8 inches (76 to more than 203 mm) of rainfall across much of the Carolinas and Virginia. A pocket of extreme rainfall occurred in the Rocky Mount-Wilson area of eastern North Carolina, with a 2-day total of 9.84 inches (250 mm) recorded at Rocky Mount-Wilson Regional Airport. On the 11th, Rocky Mount-Wilson Regional Airport, NC (2000–2020) observed its second wettest day for any month on record, with 6.02 inches (153 mm) of precipitation. On the 12th, Appomattox, VA (1937–2020) and Concord 4 SSW, VA (1950–2020) observed their second and third wettest day for any month on record, with 7.28 and 6.85 inches (185 and 174 mm) of precipitation, respectively. Hundreds of roads were flooded across these states, including the closure of I-95 near Wilson, NC. Dozens of swift water rescues were performed by emergency personnel, with five flood-related fatalities reported at a campground in Alexander County, NC. Several landslides occurred along the foothills of western North Carolina and southwestern Virginia.
- There were 3,843 severe weather reports across the Southeast region during the year, which is over 130 percent of the median annual frequency of 2,936 reports during 2000–2019. About 30 percent (1,154 of 3,843) of these reports were observed during April. The fewest number of reports occurred in South Carolina (510; 13 percent of total), while the greatest number was recorded in Georgia (873; 23 percent of total). Strong thunderstorm winds accounted for about 85 percent (3,256 of 3,843) of the severe weather reports and caused at least 10 fatalities and 34 injuries across the region. On January 11th, a thunderstorm wind gust of 75 mph (34 m/s) in Greene County, AL blew a very large tree down onto the water main in Forkland, and many thousands of gallons of water spilled out of the water tower. On January 13th, a microburst damaged a school in Sampson County, NC. Damage in the form of snapped and uprooted trees occurred to the west of the school, along with the more significant roof uplift and partial outer wall collapse of the school’s gymnasium. The maximum wind speed was estimated at 85 mph, and three injuries were associated with the microburst. On May 5th, damaging straight-line winds and an associated gustnado were observed in Lancaster County, SC, with the highest estimated gust of 105 mph. On December 24th and 25th, an extensive squall line associated with a vigorous cold frontal passage produced convective wind gusts exceeding 45 mph (20 m/s) along coastal portions of the region, including 49 mph (22 m/s) at Charleston International Airport, SC, 59 mph (26 m/s) at Brunswick Golden Isles Airport, GA and Tampa International Airport, FL, 61 mph (27 m/s) at Newport News/Williamsburg International Airport, VA, and 64 mph (29 m/s) at Billy Mitchell Airport on Cape Hatteras, NC. In addition, a 55-mph (25-m/s) wind gust reported at Gainesville Regional Airport, FL was the highest gust observed during the month of December since records began in 1973, breaking the old record of 46 mph (21 m/s) set on December 24, 2014. The highest thunderstorm wind gust recorded during the year was 84 mph (38 m/s), which was measured near Mountain Lake, VA as a squall line moved through southwestern Virginia on April 8th. The largest hailstones observed during the year were teacup-sized (i.e., 3-inch or 76-mm diameter), which were reported in Vernon, AL on March 29th, Darlington County, SC on May 5th, and Lake Mary, FL on May 21st. A total of 299 tornadoes (8 unrated, 123 EF-0s, 125 EF-1s, 31 EF-2s, 11 EF-3s, 1 EF-4) were confirmed across the Southeast during the year, which is the sixth highest annual tornado count for the region since modern records began in 1950. Twenty-five fatalities and at least 166 injuries were caused by tornadoes during the year. Nearly half (138 of 299) of the tornadoes occurred during April, which had the third highest monthly count of tornadoes across the region behind April 2011 (226) and September 2004 (247). Sixty-one tornadoes were confirmed in South Carolina, which is the state’s second highest annual count behind the 86 tornadoes observed during 2004. On April 13th, the strongest tornado of the year across the Southeast region occurred in Hampton County, SC. This EF-4 tornado, with a path length of more than 24 miles (39 km) and a maximum path width of 1,300 yards (1,189 meters), damaged and destroyed many residences, including mobile and single-family homes. The damage pattern suggested that this tornado may have had multiple vortices, which can occur with the strongest tornadoes. There were five fatalities and 65 injuries associated with this tornado, many of which occurred in the hardest hit areas just south of Estill, SC. This was the first EF-4 tornado in South Carolina since 1995, and it was the second of 12 tornadoes in a tornado family that traveled over 150 miles (241 km) from Middleground, GA to Murrells Inlet, SC. Of the 17 lightning fatalities across the United States during the year, seven occurred within the Southeast region, which is below the median annual frequency of 11 fatalities from 2000–2019. On August 5th, a 42-year-old man and a 77-year-old man were struck and killed while cleaning up debris from Hurricane Isaias in Wilmington, NC.
- Drought was largely absent across the Southeast region due to extensive periods of above-average precipitation during the year, but an episode of moderate-to-severe (D1–D2) drought did impact much of Florida and coastal Alabama from spring through early summer. From the beginning of January through mid-March, a pocket of moderate-to-severe drought persisted along the eastern half of the Florida Panhandle. Drought conditions expanded in coverage and intensified rapidly over the next month, with moderate-to-severe drought covering 83 percent of Florida by mid-April. By the middle of May, the coverage in drought was significantly reduced across Florida, but areas of severe drought remained in southwestern Florida and coastal Alabama. The area of drought in southwestern Florida persisted until early June, while the area of drought in coastal Alabama lasted until late June. Through the end of summer, most of the Southeast region remained drought-free, except for a few short-lived pockets of moderate drought in portions of northern and coastal Virginia, Georgia, southeastern Alabama, and west-central Florida. From late August through the end of the year, the mainland portion of the Southeast region remained completely drought-free for the first time since 2004. In Puerto Rico, moderate drought developed in mid-May and continued to intensify and expand in coverage through the early summer. Peaking in intensity in early July, moderate-to-severe drought conditions covered over half of the island. However, the drought was rapidly eliminated by beneficial rainfall from Tropical Storm Isaias at the end of July. A few small pockets of moderate drought developed in north-central Puerto Rico during late December. While agricultural and livestock production was satisfactory across much of the Southeast during the year, exceptional wetness and numerous landfalling tropical cyclones did produce some significant impacts. During January and February, many cattle producers were forced to rely on supplemental feedings of hay due to excessively wet pastures. Livestock producers in Georgia had to travel far to buy hay since supplies were short from the drought conditions in autumn 2019. Strawberry growers in Florida reported higher-than-normal fungal disease pressure and pest pressure due to unusual warmth in January and February. During the spring, wet conditions across portions of the Southeast disrupted the application of herbicides, fertilizers, and nutrients to fields. In Georgia, the blueberry crop was badly damaged by severe weather in April. Prolonged dryness in April and May led to an outbreak of numerous wildfires across Florida. One of the largest fires burned over 8,600 acres in Collier County and forced a portion of I-75 to close. Multiple residences were destroyed by this fire, and many residents were told to evacuate the area. During the summer, a persistent influx of tropical moisture and high humidity across much of the Southeast increased disease pressure on crops, with white mold and fungus reported on peanuts in Georgia and Florida. Excessive rainfall, paired with high humidity, in Georgia slowed the drying down of corn, with many farmers battling whiteflies and boll rot in cotton. In September, many farmers in the Florida Panhandle and southern Alabama reported a loss of cotton, peanuts, and pecans due to the passage of Hurricane Sally. Peanuts in the Florida Panhandle were unable to be dug due to rainfall from Sally, and farmers noted that fungal disease and rotting would affect the quality of the harvest. In many fields in southern Alabama, Hurricane Sally blew down the cotton crop when bolls had yet to open. Nearly 40 percent of the cotton crop in Alabama contained seed coat fragments, which is a sprouting or deterioration of the seed that occurs under extended wet conditions, reducing the quality of the cotton fiber. Pecan production was substantially impacted for this year’s crop, as many immature nuts were blown to the ground. In addition, hundreds of pecan trees were uprooted across southern Alabama, with some of the losses occurring in 90-year-old orchards. In October, Hurricane Zeta caused additional cotton losses in Georgia and the Florida Panhandle, as heavy rainfall led to an increase in boll rot. In Alabama, greenhouses and plastic bedding on vegetables were significantly damaged by Zeta’s high winds. Following the passage of Tropical Storm Eta in November, vegetable crops in southern Florida were severely damaged, with estimated costs ranging from $85 to as much as $320 million. The timing was particularly bad for farmers that were in the midst of harvesting a variety of vegetable crops bound for holiday tables, including sweet corn, green beans, lettuce, cabbage, and radishes. In parts of North Carolina, the soybean harvest was delayed due to heavy rainfall and flooding from Eta, while newly seeded livestock pastures sustained damage. During the fall, some Florida citrus growers reported extremely heavy fruit drop within their groves, which was partially attributed to premature blooming during the winter 2019–2020 season as well as a persistence of heavy rainfall throughout the year. Heavy rainfall during early December saturated vegetable fields in southern Florida, resulting in crop losses, increased disease pressure on lettuce and beans, and bloom dropping in pepper and tomato plants. Vegetable and citrus growers in southern Florida had to pump excess water out of their fields due to the persistent rainfall. While cotton producers in the Florida Panhandle continued their harvest, some noted that cotton yields were particularly poor this year from excessively wet weather. In central and eastern portions of South Carolina, heavy rainfall delayed the harvesting of row crops and the planting of small grains and cover crops. Prolonged saturated soil caused some farmers to abandon portions of their soybean and cotton fields. Wet weather continued to delay field work across North Carolina, with reports of negative impacts on the wheat crop due to waterlogged soils. Several nights of frost and freezing temperatures during the month caused some grass damage in pastures across northern and central Florida, while low-lying areas of pastures in southern Florida sustained flooding. Persistent rainfall in the Pee Dee region of South Carolina caused some health issues in livestock, including coccidia, pneumonia, and salmonella.
- For more information, please go to the Southeast Regional Climate Center Home Page.
High Plains Region (Information provided by the High Plains Regional Climate Center)
- 2020 was a year of transition for the High Plains region, as cool, wet conditions over the past two years gave way to a warmer and drier regime. Hints of this transition began in the fall of 2019, when drought conditions developed across southern Kansas and western and southern Colorado. These conditions improved slightly during the spring, but quickly gave way to further expansion and deterioration, particularly during the summer and fall. Issues with extreme wetness carried over into 2020 in parts of the Northern Plains, however. In some areas, the 2019 fall harvest extended well into 2020, and wet soils and flooding in the spring caused additional impacts to agriculture and infrastructure. Even in these areas, the wetness became a memory as drought developed and expanded in the late summer, fall, and early winter.
- Ultimately, the year ended with over 80 percent of the region in drought (D1-D4), and these conditions caused a number of impacts over the course of the year. Fires were a major issue across Colorado and Wyoming this year, with the three largest fires in Colorado’s history burning this summer and fall. These fires burned thousands of acres of forest and rangeland, caused evacuations, closed roads, and impacted air quality. From an agricultural perspective, drought caused many impacts, especially for livestock and winter wheat producers. Range and pastureland conditions were severely impacted this year, particularly in parts of Colorado and Wyoming, where livestock producers were forced to haul water or provide supplemental feed. Some producers sold calves early, too. Winter wheat was also impacted, with at least 15 percent of the crop in poor to very poor condition at the start of 2021 in Colorado (34 percent), Kansas (17 percent), and Nebraska (15 percent), according to the USDA’s National Agricultural Statistics Service. Meanwhile, for those looking to get out and enjoy the weather, fires, along with poor air quality from the smoke, impacted a range of recreational activities. Later in the season, a lack of snow cover across the Plains and low snowpack in the central Rockies also impacted skiing and snowmobiling activities.
- In a break from recent years, average annual temperatures were generally above normal across the High Plains region, with widespread departures of up to 2.0 degrees F (1.1 degrees C). Some areas of the region, especially western and southern Colorado, had departures over 2.0 degrees F (1.1 degrees C), which led to many locations ranking in the top 10 warmest years on record. Like most years, 2020 temperatures were quite variable throughout the year. The year started off on the warm side, with winter temperatures generally above normal, except for western areas of Colorado and Wyoming. Warm conditions continued into March, but, overall, spring temperatures were below normal due to cooler conditions in April and May. Temperatures rebounded in the summer, with most states in the High Plains ranking in the top 15 warmest summers on record. Meanwhile, autumn was characterized by extreme temperature swings, with October ranking in the top 10 coldest and November ranking in the top 10 warmest for some states in the region. The year ended quite warm, with a continuation of much-above-normal temperatures in December for most of the region. The following locations had notable temperature records during 2020:
- Alamosa, Colorado: New daily records for maximum and minimum temperature set in the same day (92.0 degrees F/33.3 degrees C and 37.0 degrees F/2.8 degrees C), July 10 (period of record 1906-2021)
- Rapid City, South Dakota: Earliest hard freeze (28.0 degrees F/-2.2 degrees C) on record, September 9 (period of record 1942-2021)
- Pueblo, Colorado: Most number of 90.0 degrees F (32.2 degrees C) days on record for a single year, 99 days (period of record 1888-2021)
- Denver, Colorado: Highest September temperature on record at 101.0 degrees F (38.3 degrees C), September 5 (period of record 1872-2021)
- Laramie, Wyoming: Lowest October temperature on record at -26.0 degrees F (-32.2 degrees C), October 27 (period of record 1948-2021)
- After two consecutively wet years, 2020 was an extremely dry year for the majority of the High Plains region. Many locations had precipitation totals that ranked in the top 10 driest on record, rivaling the drought years of 2017, 2012, and the Dust Bowl. This switch from wet to dry was so pronounced that some locations went from having a top 10 wettest year in 2019 to a top 10 driest year in 2020. For instance, Sioux Falls, SD had its second wettest year on record in 2018, its wettest year in 2019, and then its sixth driest in 2020 (period of record 1893-2021). Meanwhile, Bismarck, ND had its second wettest year in 2019, followed by its third driest in 2020 (period of record 1874-2021).
- Rocky Mountain snowpack was near normal for most of the 2019-20 season (July-June). Upper Missouri Basin snowpack peaked in mid-April at just above normal above Fort Peck Reservoir and between Fort Peck and Garrison Reservoirs, according to the U.S. Army Corps of Engineers. Plains snowpack was variable throughout the season. This year’s snow season (2020-2021) kicked off with several early snowfalls, starting in September. This resulted in many locations ranking among the top 10 snowiest Septembers and Octobers on record. Despite the snowfall, the fall season was dry, overall, and the majority of the region went into winter with dry soils. Soil moisture conditions in the fall and early winter are important for the High Plains region because, as soils freeze, available moisture is locked in place until spring. This could be concerning as spring planting gets underway. Rocky Mountain snowpack was below normal at the time of this writing.
- The severe weather season got off to a very slow start this year, with only 10 tornado watches issued nationally during May. The summer was much more active, however, with several notable events occurring, such as the Western U.S. derecho in June and the Midwestern U.S. derecho in August, which started in the High Plains region. Although the vast majority of the Midwestern derecho impacted areas to the east of the region, it is worth noting that this was an incredibly devastating storm that caused an estimated $7.5 billion in damage, according to NOAA’s U.S. Billion-Dollar Weather and Climate Disasters event database. This year’s severe weather season ended below the 5- and 10-year averages for the High Plains region, in terms of tornado, hail, and wind reports, according to the Storm Prediction Center. This year’s tornado reports were particularly low, with only 129 reported through October. The following locations had notable precipitation records during 2020:
- Boulder, Colorado: Highest seasonal snowfall total on record with 152.0 inches (386 cm) (period of record 1893-2021)
- Grand Forks, North Dakota: Tied for highest 1-day total precipitation of 4.26 inches (108 mm) for the month of June, June 30 (period of record 1893-2021)
- Casper, Wyoming: Earliest autumn snowfall on record with 2.3 inches (6 cm), September 7 (period of record 1939-2021)
- Cheyenne, Wyoming: Highest 1-day total snowfall of 14.0 inches (36 cm) for the month of October, October 25 (period of record 1883-2021)
- According to the U.S. Drought Monitor, there were substantial changes in drought conditions across the High Plains region over the course of the year. At the beginning of 2020, only 12 percent of the High Plains region was experiencing moderate to exceptional drought (D1-D4), and these conditions were largely confined to western and southern areas of Colorado and Kansas. Conditions improved somewhat over the winter and early spring, but then deteriorated across the region through the summer, fall, and even early winter.
- In western areas of the region, drought conditions deteriorated rapidly and caused numerous impacts to agriculture and water resources. During the summer, drought conditions expanded to include over 70 percent of Wyoming and nearly all of Colorado. These dry conditions were coupled with extreme heat, which helped fuel some of the largest wildfires in Colorado’s history. Drought conditions continued to worsen across much of the region during the fall as precipitation deficits mounted. Early season snows were promising, but merely slowed the intensification and expansion of drought. Even as the winter started, drought conditions continued to expand, which is highly unusual for the High Plains at this time of the year.
- Ultimately, the year ended with 82 percent of the region in drought, which was up 70 percent from the beginning of the year. Although drought has impacted parts of the region in recent years, such as the 2017 Northern Plains drought, this is the most expansive drought in the region since 2012-2013.
- Extreme Wetness and Flooding in the Dakotas: Although drought was the main story of 2020, extreme wetness and flooding was still an issue in some areas. In North Dakota, a major disaster was declared due to wet soils and flooding in the spring, which caused an estimated $40 million in damage to infrastructure. Meanwhile, in South Dakota, flooding along the James River continued through the winter and into the spring and summer, which is highly unusual. The James River at Columbia, SD went 518 consecutive days above flood stage - a new record for the Missouri Basin.
- April Freeze Events Impact CO and KS Agriculture: In mid-April, a hard freeze event on Colorado’s Western Slope severely impacted the state’s peach crop. Early estimates indicated that upwards of 95% of the crop was potentially lost. A USDA Disaster Declaration was requested for the impacted counties. In Kansas, a combination of drought and multiple freeze events caused damage to winter wheat in western and central areas of the state.
- Western U.S. Derecho: On June 6th, an extremely rare western U.S. derecho tracked over 750 miles, from Utah to North Dakota. According to the Storm Prediction Center, there were 339 wind reports across Utah, Colorado, Wyoming, Nebraska, South Dakota, Montana, and North Dakota, 44 of which were 75 mph (121 km/hr) or greater. Only two other western U.S. derechos have been documented in the literature.
- Historic Wildfires in CO: The three largest wildfires in Colorado’s history burned over 500,000 acres this year - the Cameron Peak Fire, the East Troublesome Fire, and the Pine Gulch Fire. These fires caused numerous evacuations of homeowners, recreators, and livestock, and damaged or destroyed over 1,000 structures. Additionally, the Cameron Peak and East Troublesome Fires burned over 30,000 acres of Rocky Mountain National Park.
- Early September Record Heat, Cold, and Snow: A strong storm system brought an unusually cold air mass, ushering in some of the earliest freezes and snowfalls on record. This storm came on the heels of record-breaking heat in the west, which set many interesting records. According to the National Weather Service in Boulder, Denver, CO had its warmest day prior to a measurable snowfall (93.0 degrees F/33.9 degrees C) and only went 3 days between its last 100.0 degrees F (37.8 degrees C) day and a measurable snowfall.
- Drought Expands across Region: Drought expanded and intensified across the region throughout 2020. Colorado and Wyoming were particularly hit hard, with dry conditions helping to fuel large wildfires. Dry conditions did allow for a quick harvest this fall, but poor pasture and range conditions were an issue for livestock producers who had to haul water and provide supplemental feed.
- For more information, please go to the High Plains Regional Climate Center Home Page.
Southern Region (Information provided by the Southern Regional Climate Center)
- The year 2020 proved to be a warm year for the Southern Region. Louisiana, Mississippi, and Texas experienced a top-10 warmest year on record, and the region as a whole had an average annual temperature of 63.58 degrees F (17.54 degrees C), making it the fourteenth-warmest year on record. There were four months (January, March, July, and November) where all six states averaged above-normal temperatures. There were two months (March and November) where the entire region experienced a top-10 warmest month on record. March was an exceptionally warm month for the region, as three states (Louisiana, Mississippi, and Texas) experienced a top-5 warmest March on record, while Oklahoma experienced a top-10 warmest March on record. For the year, there were areas in all six states that averaged between 1 to 2 degrees F (0.56 to 1.11 degrees C) above normal, while parts of Texas, Oklahoma, Louisiana, Mississippi, and Tennessee averaged 2 to 3 degrees F (1.11 to 1.67 degrees C) above normal. There were scattered areas of below normal temperatures across Arkansas that averaged 0 to 1 degrees F (0.00 to 0.56 degrees C) below normal. The statewide average annual temperatures are as follows: Arkansas - 61.15 degrees F (16.19 degrees C), Louisiana – 68.18 degrees F (20.10 degrees C), Mississippi – 65.31 degrees F (18.51 degrees C), Oklahoma – 60.70 degrees F (15.94 degrees C), Tennessee - 59.34 degrees F (15.19 degrees C), and Texas – 66.81 degrees F (19.34 degrees C). The statewide temperature rankings for 2020 were as follows: Arkansas (thirty-eighth warmest), Louisiana (ninth warmest), Mississippi (tenth warmest), Oklahoma (twenty-eighth warmest), Tennessee (thirteenth warmest), and Texas (seventh warmest). All state rankings are based on the period spanning 1895-2020.
- The 2020 annual precipitation totals indicate that precipitation for the year was above normal for much of the Southern Region, with Tennessee experiencing its sixth-wettest year on record while the region as a whole received an average annual precipitation total of 328.59 inches (8346.19 mm), making it the eleventh-wettest year on record. Every state with the exception of Louisiana had at least one month that was top-10 wettest on record, and two states (Mississippi and Oklahoma) had one month that was top-5 wettest on record. Oklahoma experienced two months that were top-10 wettest on record (fifth-wettest March on record, sixth-wettest January on record). There were three months (January, February, and September) where every state was wetter than normal and one month (November) where every state was drier than normal. Precipitation across the region ranged from 50 percent or less of normal to 130 percent or more of normal, with the driest areas in western Texas and the wettest areas across parts of every state. The statewide average annual precipitation totals are as follows: Arkansas received 63.43 inches (1611.12 mm), Louisiana received 66.40 inches (1686.56 mm), Mississippi received 68.22 inches (1732.78 mm), Oklahoma received 39.10 inches (993.14 mm), Tennessee received 65.40 inches (1661.16 mm), and Texas received 26.04 inches (661.42 mm). The statewide precipitation rankings for the year are as follows: Arkansas (eleventh wettest), Louisiana (ninteenth wettest), Mississippi (eleventh wettest), Oklahoma (twenty-seventh wettest), Tennessee (sixth wettest), and Texas (fifty-fourth driest). All state rankings are based on the period spanning 1895-2020.
- Winter was warmer and wetter than normal for most of the Southern Region, with the region experiencing its tenth-warmest winter on record. Every state experienced a warmer than normal winter, with every state experiencing a top-20 warmest winter on record while Tennessee experienced its sixth-warmest winter on record. Precipitation was primarily wetter than normal (Texas was slightly drier than normal), with Mississippi and Tennessee experiencing their sixth-wettest and eighth-wettest winters on record, respectively. December 2019 was warmer and drier than normal (with the exception of Mississippi and Tennessee, which were slightly wetter than normal), with Oklahoma and Tennessee experiencing their tenth-warmest December on record while Louisiana experienced its eighth-driest December on record. January was warmer and wetter than normal across all six states, with Texas experiencing its tenth-warmest January on record while Oklahoma experienced its sixth-wettest January on record. In February, five of six states experienced warmer than normal conditions (Texas was slightly cooler than normal) while all six states were wetter than normal, with Mississippi experiencing its fifth-wettest February on record while Tennessee experienced its eighth-wettest February on record. All state rankings are based on the period spanning 1895-2020.
- Spring was warmer and wetter than normal for the Southern Region. All six states experienced warmer than normal temperatures, with Louisiana experiencing its sixth-warmest spring on record. Every state reported wetter than normal conditions. March was mainly warmer and wetter than normal, with every state experiencing warmer than normal temperatures and every state except Louisiana experiencing wetter than normal conditions. Texas experienced its third-warmest March on record, Louisiana and Mississippi experienced their fourth-warmest March on record, Oklahoma experienced its tenth-warmest March on record, and the region as a whole experienced its sixth-warmest March on record. With respect to precipitation, Oklahoma experienced its fifth-wettest March on record while Texas experienced its seventh-wettest March on record. April was primarily cooler and wetter than normal, with every state except for Louisiana and Texas experiencing cooler than normal temperatures while every state except for Oklahoma and Texas experienced wetter than normal conditions. In May, cooler than normal conditions prevailed across every state except Texas, while precipitation was higher than normal for every state except for Mississippi. All state rankings are based on the period spanning 1895-2020.
- Summer was warmer and wetter than normal for most of the Southern Region. Every state except for Arkansas experienced warmer than normal temperatures while every state except for Oklahoma and Texas experienced wetter than normal conditions, with Texas experiencing its seventh-warmest summer on record. June was cooler than normal for every state except Oklahoma and Texas, while precipitation was mixed, as three states (Arkansas, Louisiana, and Mississippi) experienced wetter than normal conditions while three states (Oklahoma, Tennessee, and Texas) experienced drier than normal conditions. July was warmer than normal across all six states, with Texas experiencing its sixth-warmest July on record. Precipitation was primarily wetter than normal, although Arkansas and Texas were slightly drier than normal. In August, every state except for Arkansas and Oklahoma experienced warmer than normal temperatures, while every state except for Oklahoma and Texas experienced wetter than normal conditions. Arkansas experienced its seventh-wettest August on record. All state rankings are based on the period spanning 1895-2020.
- Autumn was wetter and warmer than normal for most of the Southern Region. Every state except for Oklahoma experienced warmer than normal temperatures while every state except for Texas experienced wetter than normal conditions. In September, every state except for Louisiana and Mississippi experienced cooler than normal temperatures, while every state experienced wetter than normal conditions. October was mixed with respect to temperature, with three states (Arkansas, Oklahoma, and Texas) experiencing cooler than normal temperatures while three states (Louisiana, Mississippi, and Tennessee) experienced warmer than normal temperatures. Every state except for Texas experienced wetter than normal conditions. In November, every state experienced warmer than normal conditions, with Texas experiencing its fourth-warmest November on record, Oklahoma experiencing its eighth-warmest November on record, and the region as a whole experiencing its ninth-warmest November on record. Precipitation was drier than normal across all six states. All state rankings are based on the period spanning 1895-2020.
- Drought conditions exhibited a slightly cyclical pattern throughout the Southern Region during 2020, but conditions primarily deteriorated as the year progressed. In the beginning of the year, roughly a third of the Southern Region was experiencing at least abnormally dry conditions. These conditions both improved and deteriorated through winter and into spring, with the total area experiencing at least abnormally dry conditions decreasing but the total area experiencing extreme drought conditions increasing, with a small area of exceptional drought conditions developing. During the rest of spring and beginning of summer, there was improvement in the total area experiencing drought with several areas improving to the point of only containing abnormally dry conditions. Unfortunately, in early June the total area experiencing at least abnormally dry conditions began to increase. Through summer, the total area experiencing drought or abnormally dry conditions increased, with extreme and exceptional drought conditions developing by mid-August. From September through early October conditions remained relatively steady, but by the end of October conditions began to deteriorate rapidly. The total area experiencing at least abnormally dry conditions grew from roughly one-third of the region to two-thirds of the region by the end of the year while the total area experiencing exceptional drought conditions increased. Overall, from the beginning of the year to the end of the year the region experienced a slight decrease in the total area of at least abnormally dry conditions. Within the year there was a slight increase in summer, another slight decrease during autumn, and finally a substantial increase during the winter.
- There were approximately 4,523 severe weather reports throughout the Southern Region for 2020, with 394 tornado reports, 1,310 hail reports, and 2,819 wind reports. Mississippi had the most tornado reports (127) while Texas had the most hail (601) and wind (817) reports. Conversely, Oklahoma had the fewest tornado reports (31), Tennessee had the fewest hail reports (60), and Louisiana had the fewest wind reports (256). Texas had the most severe weather reports total (1,520) while Louisiana had the fewest (407).
- There were seven tropical cyclones that directly impacted the Southern Region in 2020. Louisiana experienced five landfalls: Tropical Storm Cristobal and Hurricanes Laura, Marco, Delta, and Zeta. Texas experienced landfalls from Hurricane Hanna and Tropical Storm Beta. Hurricane Laura was the worst of the seven, making landfall as a Category 4 hurricane. Preliminary reports indicate Hurricane Laura generated a storm surge over 17 feet (5.18 meters) above ground level, which would be the largest surge on record for Louisiana. Hurricanes Hanna and Delta were primarily rain events, with reports of 15 inches (381 mm) in southern Texas from Hanna and 17 inches (431.80 mm) in southwestern Louisiana from Delta. Hurricane Zeta was responsible for wind gusts over 100 mph (160.93 kph) in southeastern Louisiana, while Hurricane Laura generated a wind gust of 133 mph (214.04 kph) in southwestern Louisiana.
- For more information, please go to the Southern Regional Climate Center Home Page.
Severe Weather and Impacts:
Western Region (Information provided by the Western Region Climate Center)
- Warm and dry conditions led to drought development in California and Nevada and major drought intensification in the Four Corners states during Calendar Year 2020. For a second year in a row the Southwest monsoon failed to produce much needed rainfall. The 2020 wildfire season in the Western U.S. was very active and several states saw the largest fires on record.
- Annual temperature departures were above normal for nearly all of the Western U.S. Long-term weather stations reported record warmth in Oregon, California, and New Mexico. All western states had stations reporting in the top ten warmest years on record. No locations reported record cold or even in the bottom ten coldest years on record. Baker City, in northeast Oregon, saw its warmest year on record going back to 1944 with an annual average temperature 48.3 °F (9.1 °C), 3.9 °F (2.2 °C) above normal. Further south, Stockton, California reported its warmest year on record (in the past 72 years) at 64.8 °F (18.2 °C), 3.5°F (1.9 °C) above normal. Oakland, California also logged its warmest year on record dating back to 1948 at 61.3 °F (16.3 °C), 3.8 °F (2.1 °C) above normal. Several other locations in central and northern California reported the second or third warmest year on record. In the Desert Southwest, Roswell, New Mexico reported its warmest year on record since records began in 1949 with an annual average temperature of 64.6 °F (18.1 °C), 3.8 °F (2.1 °C) above normal. Near record warmth was found throughout Arizona with both Phoenix (77.2 °F [25.1 °C], 2.1 °F [1.2 °C] above normal) and Tucson (72.6 °F [22.6 °C], 3.2 °F [1.8 °C] above normal) reporting the second warmest years on record.
- Many of the same locations that saw above normal and record high temperatures also experienced below normal precipitation and in some cases record dryness. California, Nevada, and the Four Corners states all received below normal precipitation with some pockets of above normal in Washington, Oregon, Idaho, and Montana. Baker City, Oregon logged a record low 3.36 in (85.34 mm), 33% of normal, for the year to accompany the record high temperatures. This record at Baker City is on the extreme end of the distribution and more than two inches less than the previous record of 5.63 in (143 mm) set in 2002. Record dryness (dating back to 1949) was also observed in Tucson, Arizona with 4.17 in (105.92 mm, 36% of normal) falling throughout the year. Well below normal precipitation was widespread throughout central and northern California with most stations reporting the second or third driest year on record. San Francisco, California, with one of the longest climate records in the state dating back to 1850, recorded its second driest year on record at 7.81 in (198.37 mm, 33% of normal). Further east, in California’s Central Valley, Sacramento received 7.86 in (199.64 mm, 39% of normal) making it the fifth driest year since 1878. The dryness extended to the east side of the Sierra Nevada into the Great Basin; Reno, Nevada saw its second driest year since 1938 with 2.72 in (69.09 mm, 37% of normal). Areas of much above normal precipitation were far more limited relative to the extent of areas that were well below normal. One of the wetter locations was northern Washington, west of the Cascades. Bellingham, Washington recorded 41.36 in (1050.54 mm, 115% of normal) making it the sixth wettest year since 1949.
- Regional snowpack, as measured by the 1 April snow water equivalent (SWE), did not stray too far from normal in 2020. Based on the 2-digit Hydrologic Unit Code watersheds, the California region had the lowest SWE at 76% of normal. The Rio Grande and Great Basin were both at 91% of normal, the Pacific Northwest and Upper Colorado both at 107% of normal, and the Lower Colorado at 108% of normal.
- Despite slightly above normal snowpack in the Colorado River Basin, April-July inflows into Lake Powell were only 52% of normal due a combination of above normal temperatures and evaporative demand and a lack of any substantial early summer monsoonal rainfall. Low reservoir levels and streamflows were contributing factors to the widespread drought intensification in 2020 throughout the West. According to the U.S. Drought Monitor, 18% of the West was in drought at the beginning of the year with no locations worse than severe drought (D2). By the end of 2020, 79% of the West was in drought and 22% of the region in exceptional drought (D4). The Four Corners region began 2020 with a sizeable area of severe drought that has expanded and intensified with exceptional drought present in Nevada, Utah, Arizona, New Mexico, and Colorado by the end of 2020. California and Nevada started the year with no drought present. The dry winter and above normal temperatures throughout the year contributed to a rapid expansion of drought in these two states with only a small area in southern California remaining drought free at the end of the year. For a small area of northwest Oregon, western Washington, and northern Idaho, drought conditions improved with removal of drought for these locations.
- The 2020 fire season was very active and ramped up in mid-summer and extended well into autumn. Many extremely large fires with rapid spread rates occurred this year with California, Oregon, and Colorado all having set records for the largest fires in the state’s history. The California fire season started slow but then exploded due to a rare dry thunderstorm event in mid-August. During a four-day period (August 16-19) 8,532 lightning strikes were detected in central and northern California that ignited 362 new fires, including the August Complex which burned 1,032,649 acres. Colorado saw its top three largest fires in 2020 which were not fully contained until late November or early December. For the West Coast fires, the exceptionally dry winter followed by a dry and hot summer and autumn were the main climate contributing factors. The drought that was already in place combined with a failure of the monsoon and well above normal temperature were the primary climate enablers of fire in the Colorado River Basin this year.
- In Alaska, annual temperatures were above normal along the North Slope, in western coastal Alaska, and the Aleutian Islands. Temperatures were below normal in the Interior, Southcentral, and Southeast regions of Alaska. Utqiagvik reported an annual temperature of 14.6 °F (-9.7 °C), 3.1 °F (1.7 °C) above normal and the 8th warmest since 1921. Nome logged its 15th warmest year on record since 1907 at 29.4 °F (-1.4 °C), 2.1 °F (1.2 °C) above normal. Precipitation for the year was above normal in the Interior and Southeast, and below normal in Southcentral and the Aleutian Islands. Cordova had its 4th driest year dating back to 1910 with 64.02 in (1626.11 mm, 71% of normal) and Kenai also saw its 4th driest year since records began in 1900 at 11.72 in (297.69 mm, 64% of normal). One of the wettest cites in Alaska, Yakutat, also had a dry year with 104.55 in (2655.57 mm, 67% of normal) making it the 6th driest on record. Meanwhile, another of the wettest cites in the state at the southern extent of Southeast Alaska, Ketchikan, logged 175.10 in (4447.54 mm, 124% of normal) making the 11th wettest year on record since 1914.
- Hawaii, for the second year in a row, saw above normal temperatures that were in some cases record-breaking. On the Big Island, Hilo recorded an annual average temperature of 76.8 °F (24.9 °C), 2.9 °F (1.7 °C) above normal and the warmest on record dating back to 1950. Five of the six warmest years on record at Hilo have occurred since 2015. Kahului, Maui also saw its warmest year on record since 1955 at 78.6 °F (25.9 °C), 2.7 °F (1.5 °C) above normal beating out the 2019 record of 78.4 °F (25.8 °C). The warmth extended northward to the island of Oahu where Honolulu recorded its 3rd warmest year on record at 78.9 °F (26.1 °C), 1.3 °F (0.8 °C) above normal. Most of the islands saw below normal precipitation with the exception of Kauai and some of southern Hawaii. The spatial extent of drought increased slightly from 18% at the beginning of the year to 19% at the end of the year. Most of the drought is focused on the central islands of Molokai, Maui, Kahoolawe, and Lanai with severe and extreme drought present.
Significant Events for Calendar Year 2020
- January: Heavy precipitation, flooding, and landslides in the Pacific Northwest: January 2020 was the 12th wettest on record for the Northwest Climate Region and the fourth wettest on record for the state of Washington. The heavy precipitation throughout the month saturated soils causing flooding of rivers flowing out the Cascades Range in Washington as well as triggering numerous landslides that affected highway travel in western Washington and northwestern Oregon.
- February: Record-breaking snowfall in central Colorado: In the Tenmile Range of central Colorado, Breckenridge and Copper Mountain ski areas both broke their February maximum snowfall records with Breckenridge logging 120 in (3048 mm) and Copper Mountain reporting 95 in (2413 mm).
- March 13-18: Heavy snow in Sierra Nevada: A deep and slowly progressing cutoff low brought heavy snowfall to the northern Sierra Nevada of California and Nevada, with snowfall totals exceeding 60 inches (1500 mm) in many locations. This ideal synoptic scenario for significant snowfall accumulation more than doubled snow depths in the northern two-thirds of the range and left snow at previously barren lower elevations. However, the gains in snow water equivalent were more modest, on the order of 3-8 in. (70-200 mm). As a result, snow drought conditions remain in the range.
- March 28: Extreme rainfall and flooding in Kauai: A cold core Kona low brought extreme rainfall to the leeward side of the Hawaiian island of Kauai. Many locations recorded more than 6 in. (150 mm) of rainfall in a 24-hour period, with Hanalei observing 8.33 in. (211 mm) of rainfall. The storm brought numerous flood-related impacts to the island, including high streamflows and road closures, forcing some evacuations.
- April: Record-breaking seasonal snowfall accumulation in the Colorado Front Range: Boulder, Colorado recorded its snowiest winter on record (dating back to 1893) with 152 inches (3861 mm) as well as its 6th snowiest April on record with 37.3 in (947 mm).
- July: Flash flooding in New Mexico: Much needed rain fell near Truth or Consequences, New Mexico, on July 27th. However, this came in a short duration with 2-3 inches falling in one hour. The city golf course, library, and police department buildings were all flooded in the event. One mobile home was reportedly lifted off of the foundation. No injuries were reported.
- July: Low reservoirs in the Rio Grande Basin, New Mexico: Major reservoirs in the Rio Grande Basin are well below normal and much lower than last year due to drought, poor summer runoff, and a weak Monsoon. Elephant Butte was 14% of average (8% of capacity) compared to 45% of average (25% of capacity) last year. All seven of the reporting reservoirs in the basin were less than 64% of average at the end of July.
- August: Massive wildfire outbreak in California: According to the National Interagency Coordination Center (Sept 1), a cumulative 1,370,707 acres burned in the Northern California geographic area with more than 13,000 firefighters and support personnel deployed to the region.
- October: Arctic sea ice extent lowest on record: According to National Snow & Ice Data Center, the October sea ice extent ranked as the lowest (63% of average) in the satellite record. This is the largest departure from average conditions seen in any month in the satellite record at 3.69 standard deviations below the 1981-2010 mean.
- December 1–2: Extreme rainfall produces mass movements in the Alaskan Panhandle: Strong and concentrated poleward atmospheric moisture transport in the form of a landfalling atmospheric river brought heavy rainfall to the Alaskan Panhandle at the start of December. Over the course of two days, the Haines Airport measured 10.26 in. (260 mm) of precipitation and Juneau Airport set a one-day precipitation record of 5.08 in. (129 mm). This storm helped Haines achieve its wettest December since records began in 1911 with a monthly total of 18.5 in. (470 mm; 300% of normal). The extreme rainfall combined with appreciable snowmelt to saturate soils and increase pore pressures. This resulted in widespread landsliding and flooding impacting 21 communities in Southeast Alaska, along with high elevation avalanches. One avalanche generated a seiche that damaged homes at Chilkat Lake. Many roads and homes were damaged or destroyed by debris flows and landslides with two people presumed dead.
- For more information, please go to the Western Regional Climate Center Home Page.