Issued 11 August 2022
Please note that the values presented in this report are based on preliminary data. They will change when the final data are processed, but will not be replaced on these pages.
National Drought Highlights
- Based on the Palmer Drought Index, severe to extreme drought affected about 33% of the contiguous United States as of the end of July 2022, a decrease of about 3% from last month. About 3% of the contiguous U.S. fell in the severely to extremely wet categories.
- About 44% of the contiguous U.S. fell in the moderate to extreme drought categories (based on the Palmer Drought Index) at the end of July.
- On a broad scale, the 1980s and 1990s were characterized by unusual wetness with short periods of extensive droughts, the 1930s and 1950s were characterized by prolonged periods of extensive droughts with little wetness, and the first two decades of the 2000s saw extensive drought and extensive wetness (moderate to extreme drought graphic, severe to extreme drought graphic).
- A file containing the national monthly percent area severely dry and wet from 1900 to present is available for the severe to extreme and moderate to extreme categories.
- Historical temperature, precipitation, and Palmer drought data from 1895 to present for climate divisions, states, and regions in the contiguous U.S. are available at the Climate Division: Temperature-Precipitation-Drought Data page. These filenames begin with "climdiv".
- According to the weekly U.S. Drought Monitor (USDM), as of August 2, 2022, 51.39% of the contiguous U.S. (CONUS) (43.16% of the U.S. including Alaska, Hawaii, and Puerto Rico) was classified as experiencing moderate to exceptional (D1-D4) drought.
Detailed Drought Overview
A subtropical high pressure ridge dominated the southern and western states during July 2022. The storm track was located far to the north, with Pacific weather systems (shortwave troughs and closed lows) moving in the upper-level circulation along the U.S.-Canadian border. Meanwhile, the North American Monsoon was active this month, producing showers and thunderstorms that gave parts of the Southwest a wetter-than-normal month. The Pacific systems dropped enough precipitation along parts of the West Coast and Northwest to give a few areas above-normal precipitation, but the rest of the West was drier than normal for July. Cold fronts dragged along by the upper-level weather systems moving in the northern storm track weakened or fell apart as they traversed the western ridge. They were re-energized over interior Canada then directed southward across the northern Plains and Great Lakes into the South where they stalled out as they encountered the southern ridge. Moisture from the Gulf of Mexico flowed north where it encountered the stalled frontal boundaries along the Ohio Valley. Showers and thunderstorms developed along the fronts and moved over the same areas in a process called training. Flooding rains were the result across the Mid-Mississippi Valley to southern Appalachians, especially in parts of Missouri and eastern Kentucky. Afternoon heating triggered convective thunderstorms in the humid air across the Southeast, resulting in areas of above-normal monthly precipitation, and the short-lived Tropical Storm Colin early in the month contributed to rain along the Carolina coast. But much of the southern and central Plains, Upper Mississippi Valley, and Northeast missed out on the rain, ending the month drier than normal. Warmer-than-normal temperatures were associated with the ridges, with the month ending up warmer than normal across most of the CONUS, especially in the Northwest to southern Plains and along the Northeast coast.
The above-normal precipitation in the Southwest, Montana, Midwest, and Southeast, as well as Alaska, contracted or reduced the intensity of drought or abnormal dryness in those areas. But hot and dry weather expanded or intensified drought or abnormal dryness in the Upper Midwest, Northeast, and other parts of the West, as well as Hawaii. The heat and dryness were especially acute in the southern Plains to Mid-Mississippi Valley where flash drought rapidly expanded or intensified. Drought expansion exceeded contraction for the CONUS, with the USDM-based national moderate-to-exceptional drought footprint across the CONUS increasing from 47.7 percent at the end of June to 51.4 percent at the end of July. Expansion exceeded contraction for the 50 states and Puerto Rico, with the total moderate-to-exceptional drought footprint increasing from 42.5 percent at the end of June to 43.2 percent at the end of July. According to USDM statistics, 40 percent or more of the CONUS has been in moderate drought or worse for the last 97 weeks. This is a record in the 22-year USDM history. The previous record was 68 consecutive weeks (June 19, 2012 to October 1, 2013).
According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 43.5 percent of the CONUS was in moderate to extreme drought at the end of July, which is slightly less than the end of June. The percent area of the CONUS in moderate to extreme drought has hovered between roughly 35 and 53 percent for the last 23 months (since September 2020).
Numerous reports of drought impacts were received during July by the National Drought Mitigation Center, and new drought declarations have been made in the counties of several states. The impacts of the drought can be seen in several drought indicators, especially in the West, central and southern Plains to Mississippi Valley, and Atlantic Coast. These include:
- dry soils (VIC, CPC [anomaly, percentile], NLDAS, and Leaky Bucket models; and GRACE surface and root zone, crop CASMA topsoil and subsoil anomaly, crop CASMA topsoil and subsoil categorical, SPoRT surface and deeper [1, 2, 3] layers, USDA [soil moisture conditions and comparison to 5-year and 10-year means] and SMOS observations);
- low ground water (GRACE, USGS) and springwater levels;
- some low streamflow levels (USGS station and huc maps);
- low number of days with precipitation and high consecutive number of days without precipitation;
- high evapotranspiration (ESI) (1-, 2-, and 3-month EDDI);
- poor vegetation (VegDRI, VCI, NESDIS satellite-based VHI, stressed vegetation, and drought risk); and
- the Quick Drought Response Index (QuickDRI).
- Many reservoir levels were low and falling in western Texas and much of the West (California; Washington; Oregon map 1, 2, 3, 4, 5; Idaho map 1, 2, 3; Southwest map 1, 2, 3, 4, 5, 6, 7, 8, 9; westwide station percentile and station and basin percent of average map), with many at or near record low levels. Lake Mead set a new record low level for July in 2022. Reservoir levels were higher in parts of the Pacific Northwest.
- Large wildfires burned throughout the month in parts of the West and Plains (wildfire maps for July 1, 5, 7, 14, 18, 21, 24, 26, 30, 31). As of July 31, over 39,000 fires had burned over 5.7 million acres nationwide; the number of fires is about 5,000 more than the ten-year average for this time of year, and the acreage burned is nearly 1.5 times the ten-year average.
Drought conditions at the end of July, as depicted on the August 2, 2022 USDM map, included the following core drought and abnormally dry areas:
Moderate (D1) to severe (D2) drought extended from the West Coast to Rocky Mountains and into the adjacent Great Plains, with large areas of extreme (D3) and pockets of exceptional (D4) drought. July precipitation was above normal across much of the Four Corners states and parts of the north and western sections, but below normal in between, especially centered in and around southern Idaho, with some areas experiencing a record dry July (low-elevation precipitation anomaly map for July; high-elevation SNOTEL station and basin precipitation anomaly maps for July; high-elevation SNOTEL station precipitation percentile map for July). In spite of the precipitation that fell during the last three months, much of the West continued to be drier than normal at longer time scales (low-elevation precipitation anomaly maps for last 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months; high-elevation SNOTEL station and basin precipitation anomaly maps for last 7, 12, 36 months; high-elevation SNOTEL station precipitation percentile maps for last 7, 12, 36 months).
- Westwide, July 2022 ranked as the 73rd driest (56th wettest) July in the 128-year record, but January-July 2022 ranked as the tenth driest January-July. August 2021-July 2022 ranked as the 41st driest such 12-month period (tied with 2007-2008), but when August 2021-July 2022 is combined with August 2020-July 2021, August 2020-July 2022 ranked as the fourth driest such 24-month period, behind August 2019-July 2021 (driest), August 1975-July 1977 (second driest), and August 2000-July 2002 (third driest). The 36-month period, August 2019-July 2022, ranked as the second driest such 3-year period, behind August 1928-July 1931.
- The percent area of the Western U.S. experiencing moderate to exceptional drought, according to USDM statistics, decreased from 75.9 percent at the end of June to 70.6 percent at the end of July.
- The percent area of the West (from the Rockies to the West Coast) in moderate to extreme drought (based on the Palmer Drought Index) fell for a fourth consecutive month, dropping to 62.7 percent at the end of July 2022.
- Moderate to exceptional drought continued in the Great Plains, especially in the southern portions, with drought expansion or intensification occurring in many areas while contraction or reduction in intensity occurred in fewer areas. In the central to northern Plains, the moderate to exceptional drought area, on balance, did not change, covering 53.2 percent of the region at the end of June and 53.2 percent at the end of July. The excessive heat and lack of precipitation led to continued flash drought in the southern Plains, with the moderate to exceptional drought area rapidly increasing from 75.9 percent at the end of June to 97.2 percent at the end of July. In the Lower Mississippi Valley, moderate to extreme drought grew from 25.3 percent at the end of June to 56.0 percent at the end of July. Taken together, the southern Plains, Lower Mississippi Valley, and Tennessee (South Region) saw moderate to exceptional drought expand from 54.9 percent at the end of June to 80.2 percent at the end of July.
- In the Midwest, drought expanded in the Ohio Valley early in the month. Heavy rains as the month progressed resulted in a reduction of drought and abnormal dryness in the Ohio Valley by the end of July. But drought expanded in northern and western parts of the region, especially in southern Missouri where flash drought rapidly intensified conditions during most of the month. The drought area in the Midwest doubled from 7.1 percent at the end of June to 18.0 percent at the end of July.
- Hot and dry conditions in the Northeast expanded and intensified drought, especially along the New England coast where severe drought developed. The regional drought area tripled from 7.5 percent at the end of June to 23.4 percent at the end of July.
- Rain in the Southeast nearly eliminated drought, with the moderate to severe drought area falling from 25.6 percent at the end of June to 1.8 percent at the end of July, just moderate drought with some abnormal dryness lingering.
- In Hawaii, drought expanded from 34.7 percent at the end of June to 39.7 percent at the end of July, with a little bit of exceptional drought developing in the Central Valley of Maui.
- In the Caribbean, moderate and severe drought contracted on Puerto Rico, with the island's drought area shrinking from 68.0 percent at the end of June to 47.8 percent at the end of July. In the U.S. Virgin Islands (USVI), extreme drought continued on St. John and severe drought continued on St. Thomas, with extreme drought reducing to severe drought on St. Croix.
In the U.S.-Affiliated Pacific Islands (USAPI), compared to last month:
- abnormal dryness ended on Majuro in the Marshall Islands; and
- severe drought was reduced to moderate drought at Kapingamarangi (Federated States of Micronesia).
Palmer Drought Index
The Palmer drought indices measure the balance between moisture demand (evapotranspiration driven by temperature) and moisture supply (precipitation). The Palmer Z Index depicts moisture conditions for the current month, while the Palmer Hydrological Drought Index (PHDI) and Palmer Drought Severity Index (PDSI) depict the current month's cumulative moisture conditions integrated over the last several months.
While both the PDSI and PHDI indices show long-term moisture conditions, the PDSI depicts meteorological drought while the PHDI depicts hydrological drought. The PDSI map may show less severe and extensive drought (as well as wet spell conditions) in some parts of the country than the PHDI map because the meteorological conditions that produce drought and wet spell conditions are not as long-lasting as the hydrological impacts.
Used together, the Palmer Z Index and PHDI maps show that short-term drought occurred in parts of California to the Great Basin, central to northern Rockies, southern and central Plains, the Lower Mississippi Valley, and parts of Florida, expanding or intensifying long-term drought (PHDI maps for July compared to June). Short-term drought also occurred in the parts of the Upper Mississippi Valley and Great Lakes and much of the Northeast, shrinking long-term wet conditions and (in coastal New England) resulting in the introduction of long-term drought. Short-term wet conditions occurred over parts of the Southwest, reducing the intensity of long-term drought, and parts of the Pacific Northwest, northern Plains, and Ohio Valley, intensifying or expanding long-term wet conditions.
Standardized Precipitation Index
The Standardized Precipitation Index (SPI) measures moisture supply. The SPI maps here show the spatial extent of anomalously wet and dry areas at time scales ranging from 1 month to 24 months.
The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Dryness is evident in the southern Plains at all time scales, in the central Plains at the 2- to 24-month time scales, and in parts of the northern Plains at the 2- and 24-month time scales. Parts of the Pacific Northwest are dry at the 1-, 2-, and 9-month time scales, with most of the Pacific Northwest dry at 24 months. Parts of the Great Basin are dry at all time scales, with the dryness extending from the Great Basin to California at the 3- to 24-month time scales. Parts of the Southwest (Four Corners States) are dry at the 6- to 12-month time scales, with all of the Southwest dry at the 24-month time scale. In fact, almost all of the West is dry at 24 months. Parts of the Northeast (especially New England) are dry at 1 to 9 months, with a hint of dryness in northern New England at 24 months. Parts of the Great Lakes are dry at 1 to 3 months. Parts of the Southeast (especially the coastal Carolinas) are dry at the 2- to 12-month time scales. An interesting pattern continues at the 24-month time scale — very dry conditions dominate across the West to western portions of the Plains, while very wet conditions dominate the Lower Mississippi Valley to Great Lakes and eastward.
Standardized Precipitation Evapotranspiration Index
The SPI measures water supply (precipitation), while the SPEI (Standardized Precipitation Evapotranspiration Index) measures the combination of water supply (precipitation) and water demand (evapotranspiration as computed from temperature). Warmer temperatures tend to increase evapotranspiration, which generally makes droughts more intense.
For the Northern Hemisphere, July is in the middle of climatological summer, which is the season when evapotranspiration is maximum. During July 2022, temperatures were much above normal across the East Coast, southern, and western states, and especially in Texas where July was record warm. The southern Plains were warmer than normal for the last 2 to 4 months, with Texas having the warmest May-July in the 1895-2022 record. At the 7-month time scale, temperatures were much warmer than normal from California to Texas, and from Florida to the Carolinas. This temperature anomaly pattern resulted in more severe SPEI values than SPI values in the Pacific Northwest to California, in the southern Plains, and in parts of the Northeast for July (SPEI map vs. SPI map), and in the southern Plains for the last two to 12 months (SPEI maps for the last 2, 3, 4, 6, 7, 9, 12 months) (SPI maps for the last 2, 3, 4, 6, 7, 9, 12 months).
California had both the driest SPEI and driest SPI for January-July 2022.
Much of the West was extremely warm during 2021 and earlier years. This increased evapotranspiration and resulted in more extreme SPEI values than SPI values at the 1- to 6-year time scales (SPEI maps for last 12, 18, 24, 36, 48, 60, 72 months) (SPI maps for last 12, 18, 24, 36, 48, 60, 72 months).
July 2022 was drier than normal across the Hawaiian Islands. Dryness was more pronounced and consistent across the western islands (Kauai, Oahu, and Molokai) than the eastern parts (Maui, Lanai, and the Big Island) at the 2- to 7-month time scales. The anomaly pattern was mixed at 9-36 months except mostly drier-than-normal on Molokai and Maui. Wetter-than-normal conditions dominated at longer time scales (last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months) (climate engine model percent of normal precipitation map for the last month).
Monthly streamflow was mostly below normal on the western islands and near normal on the eastern islands. Vegetation was stressed on parts of all of the main islands, but especially on Molokai, Maui, and Oahu (satellite analyses of stressed vegetation, drought risk, VHI). A large wildfire (the Leilani fire) developed on the Big Island near the end of the month (wildfire maps for July 24, 26, 30, 31).
Drought or abnormal dryness expanded on most of the main islands but contracted on parts of Molokai and Maui. The overall drought footprint expanded from 34.7 percent last month to 39.7 percent on the August 2nd USDM map.
July 2022 was wetter than normal across most of Alaska, with just eastern interior regions and the far Aleutian Islands drier than normal. Drier-than-normal conditions covered a larger area at the 2- to 4-month time scales, with much of the state drier than normal at 4 months. Statewide, April-July 2022 ranked as the eighth driest April-July in the 1925-2022 record. Interior areas and the Aleutian Islands were drier than normal at 6 to 7 months, with a mixed anomaly pattern in the Cook Inlet and Gulf climate divisions. At 9 to 12 months, drier-than-normal conditions were common along the Aleutians to Northeast Gulf Coast, with interior areas transitioning to wetter than normal. At longer time scales, some drier-than-normal conditions persisted along the Aleutians to Northeast Gulf Coast, but wetter-than-normal conditions became more prominent, while the panhandle had drier-than-normal areas appear at 48 to 60 months (low elevation station precipitation anomaly maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months) (high elevation SNOTEL station precipitation percentile map for the last 1, 4, 7, and 12 months) (high elevation SNOTEL station precipitation anomaly maps for July 2022 and October 2021-July 2022) (SNOTEL basin precipitation anomaly map for October 2021-July 2022) (SNOTEL basin and station precipitation anomaly maps for the last 1, 4, 7, and 12 months) (climate division precipitation rank maps for the last 1, 3, 6, 7, and 12 months) (climate engine model percent of normal precipitation map for the last month) (Leaky Bucket model precipitation percentile map).
July temperatures ranged from warmer than normal in the southeast to cooler than normal in the northwest. At the 2- to 7-month time scales, warmer-than-normal conditions spread across the southern third of Alaska. Temperatures at these time scales were cooler than the 30-year average but in the warm third of the historical record. At the 12-month time scale, temperatures were cooler than the 30-year average across most of the state but in the warmest third of the historical record in western areas (low elevation station temperature anomaly maps for the last 1, 2, 3, 4, 7, 10, 12 months) (climate division temperature rank maps for the last 1, 3, 6, 7, and 12 months) (gridded temperature percentile maps for the last 1, 3, and 7 months) (Leaky Bucket model temperature percentile map).
Above-normal July precipitation helped restore soil moisture in some areas, especially in the south. But modeled soil moisture and experimental satellite-based observations of soil moisture (SMOS; GRACE root zone and surface soil moisture; SPoRT relative percent of soil moisture for 0-10 cm [0-4 inches] depth, 10-40 cm [4-16 inches] depth, 40-100 cm [16-39 inches] depth, 100-200 cm [39-79 inches] depth) and groundwater showed lingering drier-than-normal conditions in the surface soil layers in some areas, with drier soils at deeper layers more localized in the northeast. Satellite observations of vegetative health (stressed vegetation, VHI, drought-related stress) showed stressed vegetation lingering in a few parts of the state. Several dozen large wildfires burned across the state from the southwest to northeast (wildfire maps for July 1, 5, 7, 14, 18, 21, 24, 26, 30, 31). Rain that began at mid-month helped reduce the number of fires, especially in the southwest. According to the National Interagency Coordination Center, since the beginning of the year, more than 3 million acres had burned in the state by July 31. Monthly streamflow was mostly near to above normal with some below-normal streams in the southwest.
Above-normal precipitation in July ended severe drought and reduced moderate drought to a small area in the interior northeast. The total drought area shrank from 15.6 percent of the state at the end of June to 0.7 percent by the end of July.
Puerto Rico and U.S. Virgin Islands
July 2022 was mostly wetter than normal across Puerto Rico (PR) and the U.S. Virgin Islands (USVI). The last 2 months had a mixed precipitation anomaly pattern, with drier-than-normal conditions dominating at 3 to 4 months. In the USVI, King Airport on St. Thomas had the fifth driest May-July and sixth driest April-July in the 1953-2022 record; Rohlsen Airport on St. Croix ranked eleventh driest for April-July in the 1951-2022 record and sixth driest for August-July; and Windswept Beach on St. John had the second driest April-July and May-July and fourth driest August-July in the 1984-2022 record. The precipitation anomaly pattern across PR and the USVI was mixed at 6 to 7 months, and mostly drier than normal at longer time scales (radar-based precipitation anomaly estimates for the last 1, 2, 3, 6, 7, 10, 12 months) (low elevation station precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months) (climate engine model percent of normal precipitation map for the last month: PR and USVI, Caribbean and Gulf of Mexico region).
Root zone analyses indicated that soil conditions were dry along the southern and northern coasts into the interior of PR and across the USVI (root zone soil saturation fraction; relative soil moisture at 0-10 cm [0-4 in], 10-40 cm [4-16 in], 40-100 cm [16-39 in], 100-200 cm [39-79 in] depth). Satellite analyses show areas of vegetative stress (VHI for PR and USVI, drought risk for PR and USVI, stressed vegetation for PR and USVI). Monthly streamflow on PR was improved compared to last month with just a few gauges below normal. In the USVI, groundwater during July continued to steadily decline on St. John, declined rapidly near the end of the month on St. Thomas, and declined then leveled off near the end of the month on St. Croix. The groundwater level on St. Thomas set a new record low value (in the 2016-2022 record) on July 31. The groundwater level on St. Croix continued to set new record low values during July, compared to the 2016-2022 record. The July groundwater level on St. John was at the lowest level since November 2016. Drought contracted on PR. Moderate to severe drought covered 68.0 percent of the island at the end of June, but decreased to 47.8 percent by the end of July. As of August 2, PR has been in drought for a record 85 consecutive weeks. In the USVI, at the end of July, extreme drought continued on St. John, severe drought continued on St. Thomas, and extreme drought improved to severe drought on St. Croix.
CONUS State Precipitation Ranks
July 2022 was drier than normal across much of the West and southern Plains to Mid-Mississippi Valley, as well as parts of the Upper Mississippi Valley to Northeast. Twelve states had a precipitation rank in the driest third of the 128-year historical record for July, including three in the top ten driest category — Rhode Island (second driest), Texas (fifth driest), and Connecticut (tenth driest).
May-July 2022 was drier than normal across California to the Great Basin, the southern and central Plains to Mississippi Valley, much of the Northeast, and parts of the Southeast. Seventeen states had a precipitation rank in the driest third of the historical record for May-July, including two in the top ten driest category — Texas (fifth driest) and Massachusetts (eighth driest).
The last six months (February-July 2022) were drier than normal across much of the West and southern to central Plains, and parts of the Lower and Upper Mississippi Valley and coastal Southeast to New England. Eighteen states had a precipitation rank in the driest third of the historical record for February-July, including four in the top ten driest category — California (second driest), Nevada and Texas (fourth driest), and Utah (eighth driest).
The year to date (January-July 2022) had a similar precipitation anomaly pattern to the last six months — drier than normal across much of the West and southern to central Plains, and parts of the Lower and Upper Mississippi Valley, Great Lakes, and coastal Southeast to New England — except the dryness was more intense in the West and Plains. Record dry conditions occurred locally in the West and southern Plains. Sixteen states had a precipitation rank in the driest third of the historical record for January-July, including the same four in the top ten driest category — California (driest on record), Nevada and Texas (second driest), and Utah (fourth driest).
The last 12 months (August 2021-July 2022) also had a similar precipitation anomaly pattern to the last two time periods — drier than normal across much of the West and southern to central Plains, and parts of the Lower and Upper Mississippi Valley, coastal Southeast, and New England. Fourteen states had a precipitation rank in the driest third of the historical record for August-July, including one in the top ten driest category — Texas (fifth driest).
During July 2022, the Primary Corn and Soybean agricultural belt had a mixed temperature and precipitation anomaly pattern. The month ranked as the 49th wettest and 34th warmest July, regionwide, in the 1895-2022 record.
March marks the beginning of the growing season for the Primary Corn and Soybean belt. March-July 2022 was generally wetter and warmer than normal in the south and east, and drier and cooler than normal to the northwest. The period ranked as the 31st warmest and 60th driest March-July, regionwide, on record.
According to the U.S. Department of Agriculture (USDA), as of August 2, 2022, drought affected approximately 49 percent of barley production, 31 percent of corn production, 65 percent of cotton production, 85 percent of rice production, 81 percent of sorghum production, 28 percent of soybean production, 17 percent of spring wheat production, 58 percent of winter wheat production, 47 percent of hay acreage, 60 percent of the cattle inventory, 48 percent of the milk cow inventory, and 60 percent of the sheep inventory. Based on July 31 USDA statistics, 14 percent of the corn crop, 11 percent of the soybean crop, 7 of the spring wheat crop, and 49 percent of the nation's pasture and rangeland were in poor to very poor condition, and 45 percent of the nation's topsoil and 47 percent of the subsoil were short or very short of moisture (dry or very dry). The table below lists those states having 30 percent or more of topsoil or subsoil moisture short or very short, or 30 percent or more of the pasture and rangeland or corn, soybean, or spring wheat in poor or very poor condition:
U.S.-Affiliated Pacific Islands
The NOAA National Weather Service (NWS) offices, the Pacific ENSO Applications Climate Center (PEAC), and partners provided reports on conditions across the Pacific Islands.
In the U.S. Affiliated Pacific Islands (USAPI) (maps — Federated States of Micronesia [FSM], Northern Mariana Islands, Marshall Islands [RMI], Republic of Palau, American Samoa, basinwide), July 2022 was drier-than-normal in Palau, the southern FSM, and parts of the Marshalls. It was near to wetter than normal in the Marianas and American Samoa, and the rest of the Marshalls and FSM.
Monthly precipitation amounts were below the monthly minimum needed to meet most water needs (4 inches in the Marianas and Pago Pago, and 8 inches elsewhere) at Fananu. July precipitation was above the monthly minimums at the rest of the stations across the USAPI. The 4- and 8-inch thresholds are important because, if monthly precipitation falls below the threshold, then water shortages or drought become a concern.
The tropical Pacific climatology can experience extremes in precipitation, from very low precipitation during the dry season to very high precipitation during the wet season. This can result in monthly normal precipitation values that are different from the monthly minimum needed to meet most water needs, and this can lead to percent of normal values that seem odd. This was the case during July 2022, which is in the wet season for most locations in Micronesia. Precipitation was above the monthly minimum but below normal (1981-2010 normal), because the normals are high, at:
- Airai: July 2022 precipitation 13.31 inches, July normal mean 18.12 inches, July normal median 18.53 inches
- Kapingamarangi: July 2022 precipitation 8.60 inches, July normal mean 13.16 inches, July normal median 14.15 inches
- Lukunor: July 2022 precipitation 10.52 inches, July normal mean 16.46 inches, July normal median 15.93 inches
- Kwajalein: July 2022 precipitation 9.23 inches, July normal mean 9.85 inches, July normal median 9.87 inches
- Majuro: July 2022 precipitation 10.70 inches, July normal mean 11.93 inches, July normal median 11.17 inches
In the table below, the station identified as Koror is Palau International Airport (Airai).
As measured by percent of normal precipitation, Kapingamarangi and Lukunor were drier than normal in the short term (July and the last 3 months [May-July 2022]) and long term (year to date [January-July 2022] and last 12 months [August 2021-July 2022]). Pago Pago was drier than normal in the long term but wetter than normal in the short term. Majuro was drier than normal in the short term but wetter than normal in the long term. Guam was near to wetter than normal for July and the last 12 months, but drier than normal for the other 2 time periods. Airai and Kwajalein were drier than normal for July but near to wetter than normal for the other 3 time periods. Chuuk, Kosrae, Pohnpei, Saipan, and Yap were near to wetter than normal in the short-term and long-term.
Based on percent of normal average (instead of normal median values), in the Marianas Islands, precipitation during July and June-July was above normal across the main islands. The last 3 to 9 months were generally drier than normal on Guam with a mixed or wet anomaly pattern on Saipan and Rota. Wetter-than-normal conditions dominated at the 10- to 12-month time scales, while drier-than-normal conditions dominated at longer time scales (percent of normal precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months).
Based on percent of normal average (instead of normal median values), in the Marshall Islands, precipitation during the last 1 to 4 months was above normal at the regular-reporting stations except one or two islands in the northeast or south where it was below normal. Wetter-than-normal conditions dominated for the 6- to 12-month time scales, with a mixed anomaly pattern at longer time scales (percent of normal precipitation maps for the last 1, 2, 3, 4, 6, 7, 9, 10, 12, 24, 36, 48, 60 months).
According to the July 31st USDM produced for the USAPI, abnormal dryness ended at Majuro and severe drought was reduced to moderate drought on Kapingamarangi. The rest of the USAPI stations were free of drought and abnormal dryness.
The National Weather Service (NWS) office in Guam issued one Drought Information Statement (DGT) for drought in July (on July 22) that noted that water levels for both private and public water tanks on Kapingamarangi were above 50% of capacity and vegetation was still yellow.
The reservoir level on Majuro generally held steady for the first half of July but then steadily rose during the last half, ending the month with about 22.2 million gallons of water. This is below the threshold of concern for drought of 28.8 million gallons. Some of the low water level is due to one sector of the reservoir being serviced. This portion of the reservoir system typically holds 8 million gallons, so the 22.2 million gallon level was above the revised 20.8 million gallon level of concern.
Satellite observations of vegetation health (VHI, stressed vegetation, drought stress) on Guam indicated a few parts of the island were still experiencing lingering stress, but most areas had no indication of drought.
Wet weather in July improved precipitation ranks at most stations, but record dryness was still occurring at Kapingamarangi at some time scales:
- Kapingamarangi: tenth driest July (in a 33-year record), but driest May-July, April-July, & March-July; 2nd or 3rd driest rank for all other longer time periods (February-July through August-July).
- Lukunor: third driest June-July and fourth driest May-July (38 years).
- Ulithi: fifth driest June-July (38 years).
- Jaluit: seventh driest May-July (38 years).
- Pago Pago: 13th wettest July (57 years of data), but seventh driest September-July.
At the wet end of the scale, no station had the wettest July on record but several ranked wettest or second wettest on record for several multi-month time periods.
The following analysis of historical data for the USAPI stations in the Global Historical Climatology Network-Daily (GHCN-D) dataset, augmented with fill-in data from the 1981-2010 Normals, helps put the current data into historical perspective by computing ranks based on the period of record. The table below lists the precipitation ranks for July 2022, February-July 2022 (last 6 months), and August 2021-July 2022 (the last 12 months). Some stations have a long period of record and their dataset is fairly complete, while other stations have a shorter period of record and the dataset has some missing data.
|Station||July 2022||Feb-Jul 2022||Aug 2021-Jul 2022||Period of Record|
SPI values for seven time periods for Pacific Islands, computed by the Honolulu NWS office.
NOAA Regional Climate Centers
More information, provided by the NOAA Regional Climate Centers and others, can be found below.
As noted by the Southeast Regional Climate Center, temperatures across the Southeast region for the month of July were slightly above normal, up to 2 degrees F (1.1 degrees C), in most areas. Above-normal precipitation was recorded across the majority of the region, except in northwest Alabama, central-western Georgia, central Virginia, and central and southern Florida.
Drought conditions improved over the majority of the Southeast in July, particularly in North Carolina, South Carolina, and Georgia. The pockets of severe drought (D2) that existed in these three states at the beginning of July were eliminated by the end of the month. The percentage area without drought increased across the region during the month, with the largest increases in South Carolina (74%), North Carolina (47%), and Georgia (46%). For the region overall, the percentage area without drought increased to 70% by July 26th, relative to 37% on July 5th. Abnormally dry (D0) conditions, however, covered 30% of the region at the end of July. Drought conditions in south-central Virginia persisted, with abnormally dry (D0) conditions and moderate drought (D1). Across Florida, abnormally dry (D0) conditions in the panhandle were alleviated, but abnormally dry (D0) conditions remained in pockets of the eastern peninsula. In NW Alabama, abnormally dry (D0) and moderate drought (D1) conditions persisted. In Puerto Rico, drought conditions did not change much over the course of July, with 85% of the island having abnormally dry (D0) conditions and 48% having moderate drought (D1). Similarly, the drought conditions in the Virgin Islands remained the same, with extreme drought (D3) conditions occurring everywhere except Saint Thomas, which had severe drought (D2) conditions.
Precipitation brought widespread increases in topsoil and subsoil moisture levels. The areal extent of topsoil with moisture levels suitable for crop growth increased in every state of the region (except Florida), with the largest increases occurring in Georgia (62% increase) and North Carolina (56% increase). Increased precipitation over much of the region provided relief to farmers after a dry June. In North Carolina, dry weather during June limited the growth of watermelon crop, but recent rain and heat has improved the outlook of watermelon production. Likewise, the peanut crop in Georgia has improved with recent rains, although disease pressure with the associated increases in humidity has become significant. The cotton crop in Georgia continues to progress well. Although corn stalks have not been growing as well across the region, recent rains have improved the outlook, with farmers in Virginia expecting a plentiful harvest of sweet corn. Furthermore, extreme heat in Alabama greatly impacted livestock, which have gained less weight than normal as they seek more shade and as a result of lower quality pasture grass due to the heat and dryness.
As explained by the Southern Regional Climate Center, July 2022 was the second hottest July on record across the Southern region, 0.3 F below July 2011. Leading the way was Texas, warmest on record at 87.3 F. All other states in the Southern region were top ten warmest. Precipitation in the Southern region was dry toward the west and wet toward the east. Texas had its fifth driest July on record at 0.95 inch and Oklahoma had its 24th driest July on record at 1.52 inches.
Dry conditions continued to expand across the region. Between June 28 and August 2, the proportion of the region that was at least abnormally dry increased from 82% to 90% and the drought area expanded from 54% to 80%. Texas in particular was fairly hard hit, with 62% of the state in extreme or worse drought. Oklahoma and Arkansas saw rapid degradations, sometimes referred to as a flash drought. Oklahoma went from 15% severe or worse drought on June 28 to 92% severe or worse drought on August 2, and Arkansas went from 0% severe or worse to 49% severe or worse. Livestock sales in Texas and Oklahoma were much larger than usual, wildfires were numerous, agricultural yields were down, and in Texas many water suppliers were restricting water use. The situation was particularly severe in South Texas, where the Falcon Reservoir along the Rio Grande has a capacity of over 2.6 million acre feet but was dropping below 10% of capacity. The prospect loomed of negative allocations, when the watermaster takes away the rights to water in the reservoir that had already been allocated to certain users.
As described by the Midwest Regional Climate Center, the July average temperature for the Midwest was 73.6 degrees F (23.1 degrees C), which was 0.8 degrees F (0.5 degrees C) above the 1991-2020 normal, and July precipitation was 4.47 inches (114 mm), which was 0.37 inch (10 mm) above normal, or 104 percent of normal. Precipitation was highest in the southeast and lowest in the west. In Minnesota, the University of St. Paul recorded the driest July in 62 years, with 1.37 inches (34.8 mm). Marshfield, Missouri, had the 6th driest July since 1908 with 1.01 inches (25.7 mm) and a 22-day stretch with no measurable rainfall.
Drought intensified across the Midwest throughout July. By month's end, dryness and drought affected over 41 percent of the region. The greatest increases in intensity and spatial extent were in Missouri, where 50 percent of the state was in drought by late July, including 18 percent in extreme (D3) drought on the U.S. Drought Monitor map. Total corn crop loss was reported in several southwest Missouri counties, along with feed shortages for livestock and declining surface water supplies. Drought lingered in western Iowa and intensified in southern Minnesota, eastern Michigan, central Illinois, and western Kentucky in July. Drought improved and was eliminated from eastern Kentucky and southern Indiana.
As explained by the Northeast Regional Climate Center, a hot, mostly dry July allowed drought to intensify, particularly in New England. The Northeast's average temperature for July was 71.5 degrees F, 1.3 degrees F warmer than normal. During July, the Northeast received 3.73 inches of rain, 86 percent of normal. State precipitation during July ranged from 27 percent of normal in Rhode Island to 122 percent of normal in West Virginia, with nine of the 12 states being drier than normal.
The USDM released on July 7 showed 2 percent of the Northeast in moderate drought and 12 percent as abnormally dry. Conditions deteriorated during July due to factors such as increasing precipitation deficits, reduced streamflow, below-normal groundwater levels, low soil moisture, above-normal temperatures, and impacts on water resources and agriculture. Severe drought was introduced in southern New England and moderate drought was introduced or expanded in New England, New York, Pennsylvania, New Jersey, and Delaware. Abnormal dryness also expanded in almost every Northeast state. The USDM released on July 28 showed 3 percent of the Northeast in severe drought, 18 percent in moderate drought, and 28 percent as abnormally dry.
Multiple waterways, including the Ipswich and Parker rivers in northeastern Massachusetts, observed record or near-record low flows. Water levels in reservoirs declined during the month. Some wells ran dry in Maine, western Vermont, central New York, and northern Pennsylvania, leading some farmers and an entire community to truck in water. Stonington, Maine, purchased and trucked in 64,000 gallons of water at a cost of around seven thousand dollars due to below-normal precipitation and increased number of seasonal residents and visitors. Communities such as Pembroke and Attleboro in Massachusetts and Vineland, New Jersey, had critically low water levels or difficulty meeting demand, leading to issues such as reduced water pressure and/or discolored water. Water restrictions were enacted, and in some locations enhanced, in multiple communities in New England, New York, and New Jersey. As of late July, more than 100 towns in Massachusetts and fifty-four New Hampshire water systems had mandatory water restrictions in place.
Farmers relied heavily on irrigation, in some cases earlier and for longer periods than usual. Several growers noted increased workloads and costs due to irrigation demands. Irrigation ponds ran low in some spots in New York, New England, and western Pennsylvania. In some of these same areas, the dry conditions contributed to reduced peach yields, stunted corn, stressed soybeans, and small cucumbers. There were also concerns for reduced yields of second and third cuts of hay in several locations, causing a central New York farmer to supplement feed for his cattle. Crop losses were noted in northeastern Massachusetts. A western Pennsylvania farmer bought crop insurance for the first time due to dry conditions. Many lawns experienced drought stress, turning brown and crunchy. Dry grass and shrubs increased fuels available to fires, while below-normal or dry waterways meant limited water supplies to fight fires, particularly in Massachusetts which saw an uptick in drought-related fire activity and fires that burned deeper and were harder to control. Fire restrictions were implemented in several New Jersey counties. The dry conditions stressed trees, making them more prone to insects and disease.
As summarized by the High Plains Regional Climate Center, the hot and dry conditions that started at the end of June carried over into July. Much of the region experienced temperatures 2 to 4 degrees F above normal. Temperatures were scorching hot throughout most of July, with relief finally coming towards the end of the month. While precipitation was spotty, the amounts were plentiful in areas that received it. Drought-afflicted areas such as southwestern Nebraska and western Kansas continued to have below-normal precipitation.
The warm and dry conditions throughout much of the month led to the intensification of drought conditions in the southern part of the region. Overall, there was a 3 percent increase in moderate to exceptional (D1-D4) drought in July. North Dakota continues to remain drought-free. Numerous days of extreme heat and a lack of precipitation led to a significant increase in drought conditions across western Kansas. Most notably, D4 increased 7 percent by the end of July and 25 percent of the state is experiencing extreme to exceptional (D3-D4) drought. Nebraska and Wyoming also experienced intensification, with D3 conditions increasing 5 and 3 percent, respectively. Drought conditions did improve in the southwestern parts of Colorado; however, they deteriorated along the Front Range. Elsewhere in the region, other improvements and degradation were observed.
The ongoing drought has taken its toll on agricultural conditions, particularly in Kansas and Nebraska. Corn was rated 33 percent and 22 percent poor to very poor, respectively. Farmers in western Kansas have started filing for crop insurance due to expected poor yields. Sorghum is a fairly drought-resistant crop, however, over 30 percent is rated poor to very poor in both Kansas and Nebraska. Pasture and rangelands are also struggling, with over 30 percent rated very poor in both states. With a lack of feed, there has been a surge in cattle sell-offs.
As described by the Western Regional Climate Center, the first week of July saw an anomalously strong area of low pressure off the West Coast with below-normal temperatures in California and western Nevada and even some rare July precipitation for parts of central-coastal California. A more summer-like pattern returned for the rest of the month with the Four Corners high establishing and the Southwest monsoon becoming more active bringing above-normal precipitation to parts of Arizona, New Mexico, and southern Nevada. Temperatures were above normal for nearly the entire West except for parts of coastal California and Oregon.
The highest precipitation totals for the month were found in Arizona and New Mexico as the Southwest monsoon flow became well established. Precipitation was above normal for most of Arizona, northwest New Mexico, southern Utah, and southern Nevada. The spotty nature of the convective monsoon rains left some places very wet with nearby locations very dry. Zero precipitation was recorded for the month for most of California outside of the northern coast as well as northwest Nevada and the northern Great Basin in Oregon and Idaho.
According to the USDM at the end of July, 71 percent of the West was in drought with 29 percent of the West in extreme (D3) or exceptional (D4) drought. Drought reductions of up to two categories were found in Arizona, New Mexico, and Montana. Small areas of one category drought expansion were found in California, Nevada, Oregon, and Washington.
Rainfall in Alaska was near to above normal in most places except for parts of the eastern Interior and lower Alaska Peninsula. Southcentral Alaska saw more than 200 percent of normal rainfall which led to elimination of drought in the region. Fairbanks was in a region of below-normal precipitation with 0.51 inch (13 millimeters), 23 percent of normal, making it the fourth driest on record. Temperatures were near normal for much of the state due to a warm start to the month followed by cooler conditions. Southeast Alaska was slightly warmer than normal with western and northern Alaska slightly cooler than normal.
Dry conditions prevailed across all of Hawaii during July. Lihue saw its eighth driest July with 0.92 inch (23.4 millimeters), 53 percent of normal, Kahului logged 0.09 inch (2.3 millimeters) for 17 percent of normal and the 11th driest on record, and Hilo received 5.39 inches (136.9 millimeters) for 58 percent of normal and the 12th driest on record. According to the USDM, 40 percent of Hawaii was in drought at the end of July with the worst conditions found on Maui where a small area of exceptional drought (D4) was present.