Issued 14 September 2022

August 2022 Palmer Z-Index
U.S. Percent Area Wet or Dry January 1996 - August 2022
August 2022 /monitoring-content/sotc/drought/2022/08/ca-p-reg004dv00elem01-01082022.gif

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

Detailed Drought Overview

A high pressure ridge dominated western portions of North America during August 2022. The ridge pushed the storm track/jet stream far to the north, with Pacific weather systems (shortwave troughs and closed lows) moving in the upper-level circulation across central to northern Canada. The ridge kept much of the West warmer than normal for the month, with record warmth occurring in the Northwest. While Pacific weather systems were deflected away, leaving the West Coast and Pacific Northwest drier than normal, the North American Monsoon brought above-normal precipitation to much of the Southwest and southern to central Rockies. The monsoon was fed by anomalous moisture from the Pacific. The monsoon precipitation and clouds kept monthly temperatures near to cooler than normal over Arizona and New Mexico. The ridge stretched across most of the CONUS during the first half of the month, but a long-wave trough developed over the eastern CONUS during the last half. The upper-level Pacific systems plunged southward across the Midwest to Northeast as they moved through the trough. They dragged cold fronts with them, with some fronts stalling out across the Midwest and even as far south as the Gulf Coast states. The fronts were starved of moisture as they crossed the northern and central Plains, resulting in a drier-than-normal month there. But they encountered Gulf of Mexico moisture over the Midwest and Deep South, where the month ended up wetter than normal. In the South, showers and thunderstorms that developed along a stalled front moved over the same areas in a process called training. Flooding rains were the result across parts of northeast Texas to Mississippi. Parts of the East Coast missed out on the rain, with drier-than-normal conditions especially notable across southern New England to New Jersey. The clouds and frontal rains kept temperatures near to cooler than normal in the Southeast to Midwest, but the month averaged warmer than normal in the Northeast with some record warmth occurring.

The above-normal precipitation in the West, southern Plains to Lower and Mid-Mississippi Valley, and parts of the Ohio Valley, Great Lakes, and northern New England, as well as Puerto Rico, 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 parts of the Pacific Northwest to northern Plains, central Plains to parts of the Ohio Valley, parts of the Northeast and southern Florida, and much of Hawaii. Drought contraction exceeded expansion with the USDM-based national moderate-to-exceptional drought footprint across the CONUS decreasing from 51.4 percent at the end of July to 45.5 percent at the end of August (from 43.2 percent to 38.2 percent for the 50 states and Puerto Rico). According to USDM statistics, 40 percent or more of the CONUS has been in moderate drought or worse for the last 101 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 40.1 percent of the CONUS was in moderate to extreme drought at the end of August, which is slightly less than the end of July. The percent area of the CONUS in moderate to extreme drought has hovered between roughly 35 and 53 percent for the last 24 months (since September 2020).

Numerous reports of drought impacts were received during August by the National Drought Mitigation Center. The impacts of the drought can be seen in several drought indicators, especially in the West, central and southern Plains to Mississippi Valley, and Northeast. These include:

D0-D4D1-D4D2-D4D3-D4D4

Drought conditions at the end of August, as depicted on the August 30, 2022 USDM map, included the following core drought and abnormally dry areas:

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.

August 2022 Palmer Z-Index
August 2022 PHDI

Used together, the Palmer Z Index and PHDI maps show that short-term drought occurred in the central Plains, Northeast, and Carolinas, expanding or intensifying long-term drought (PHDI maps for August compared to July). Short-term drought also occurred in the Pacific Northwest and northern Plains, contracting long-term wet areas and intensifying areas with long-term drought. Short-term wet conditions occurred over much of the Southwest and southern Plains, contracting or reducing the intensity of long-term drought, and over the Lower Mississippi Valley, eliminating drought in parts and initiating long-term wet conditions in other parts.

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.

August 2022 SPI
July-August 2022 SPI
June-August 2022 SPI
March-August 2022 SPI

The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Dryness is evident in the central Plains at all time scales, in the southern Plains at the 3- to 24-month time scales, and in parts of the northern Plains at the 1- to 3-month 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. Southern parts of the Northeast are dry at the 1- to 12-month time scales. Parts of the Mid-Atlantic to Carolinas coast are dry at the 1- and 3- to 12-month time scales. Parts of the Upper Mississippi Valley have dryness at 3 and 24 months. Dry conditions in the West, particularly California to the Great Basin, show up at 6 to 12 months, with most of the West dry at 24 months. 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.

December 2021-August 2022 SPI
September 2021-August 2022 SPI
September 2020-August 2022 SPI

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, August is at the end of climatological summer, which is the season when evapotranspiration is maximum. During August 2022, temperatures were much above normal across most of the West and Northeast, with record warm temperatures common. The southern Plains were warmer than normal for the last 3 to 4 months, with Texas having the second warmest summer in the 1895-2022 record. The southern and eastern states were much warmer than normal at the 6-month time scale, with most of the CONUS much warmer than normal at 12 months. This temperature anomaly pattern resulted in more severe SPEI values than SPI values in the Pacific Northwest to California, and in parts of the Northeast, for the last 1 to 3 months, in the Northeast and Texas at 6 to 8 months, and in the southern to central Plains and much of the West at 12 months (SPEI maps for the last 1, 3, 6, 8, 12 months) (SPI maps for the last 1, 3, 6, 8, 12 months).

The heat gave Oregon and Washington the second driest August SPEI in the 1895-2022 record (1967 had the driest for both). The corresponding SPI values were far less extreme. California had the driest January-August SPEI and SPI, although the magnitude of the SPEI was more extreme than the SPI.

As noted earlier, much of the West has been extremely warm during the last several 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, 24, 36, 48, 60, 72 months) (SPI maps for last 12, 24, 36, 48, 60, 72 months).

Regional Discussion

Hawaii

August 2022 was drier than normal across most of the Hawaiian Islands. The dry pattern extended over the last 2 to 8 months with the dryness most pronounced and consistent across Oahu to parts of the Big Island. Kahului had the driest January-August, February-August, and March-August, second driest April-August, seventh driest May-August, third driest June-August, and fifth driest July-August in the 1955-2022 record. Honolulu ranked sixth driest for June-August and eighth driest for March-August for 1941-2022, while Hilo had the seventh driest July-August in the 1950-2022 record. The precipitation anomaly pattern across the state was mixed at 9 to 48 months, with wetter-than-normal conditions dominating at 60 months (last 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 24, 36, 48, 60 months) (climate engine model percent of normal precipitation map for the last month).

Monthly streamflow was near to below normal on Kauai but mostly below to much below normal, with some record low values, on the islands to the east. Vegetation was stressed on parts of all of the main islands, but especially on Molokai, Maui, Oahu, and leeward parts of the Big Island (satellite analyses of stressed vegetation, drought risk, VHI). A large wildfire (the Leilani fire) burned on the Big Island for much of the month (wildfire maps for August 1, 4, 13, 18, 21, 24, 30, 31), scorching close to 20,000 acres according to the National Weather Service (NWS). Drought impact reports received by the NWS include pastures in bad shape in leeward areas of the state, and the Upcountry and West Maui water systems were in a Stage 1 Water Shortage declaration, which means the Dept of Water Supply has asked for cutbacks in use for non-essential purposes.

Drought or abnormal dryness expanded this month on most of the main islands. The area of moderate to exceptional drought jumped from 39.7 percent of the state at the end of July to 94.0 percent on the August 30th USDM map. This value is a record extent for Hawaii in the USDM 2000-2022 period of record.

Alaska

August 2022 was drier than normal in eastern interior regions and some southern panhandle and northwest coastal locations; the month was wetter than normal across the rest of Alaska. The drier-than-normal areas continued at the 2- to 6-month periods and expanded to include the Aleutian Chain, with the eastern interior region having the most intense anomalies. All of the panhandle was wetter than normal for the year to date while dryness continued in the other areas. At 12 to 24 months, scattered stations in the eastern interior and Gulf Coastal areas were drier than normal, with the Aleutians having regional dryness. Wetter-than-normal conditions dominated at longer time periods except in the south (low elevation station precipitation anomaly maps for the last 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 24, 36, 48, 60 months) (high elevation SNOTEL station precipitation percentile map for the last 1, 3, 5, 8, and 12 months) (high elevation SNOTEL station precipitation anomaly maps for August 2022 and October 2021-August 2022) (SNOTEL basin precipitation anomaly map for October 2021-August 2022) (SNOTEL basin and station precipitation anomaly maps for the last 1, 3, 5, 8, and 12 months) (climate division precipitation rank maps for the last 1, 3, 6, 8, and 12 months) (climate engine model percent of normal precipitation map for the last month) (station percent of normal map for August from ACCAP) (Leaky Bucket model precipitation percentile map).

August temperatures ranged from warmer than normal in the panhandle, southern coastal, and eastern interior regions and cooler than normal in the northwest, western coastal, and Aleutian areas. Warmer-than-average temperatures dominated at longer time scales, when compared to the long-term (1926-2022) average. But when compared to more recent (1991-2020) normals, cooler-than-normal temperatures dominated because of a pronounced warming trend in recent decades (low elevation station temperature anomaly maps for the last 1, 2, 3, 4, 8, 11, 12 months) (climate division temperature rank maps for the last 1, 3, 6, 8, and 12 months) (gridded temperature percentile maps for the last 1, 3, and 8 months) (Leaky Bucket model temperature percentile map).

Above-normal July and August precipitation helped restore soil moisture in many 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 soil moisture conditions especially in some eastern interior regions. Satellite observations of vegetative health (stressed vegetation, VHI, drought-related stress) showed stressed vegetation lingering in a few parts of the state, especially the northeast, southwest, and panhandle. A couple dozen large wildfires were burning across the state at the beginning of the month, but they had been largely extinguished or contained by the end of the month (wildfire maps for August 1, 4, 6, 13, 18, 21, 24, 30, 31). According to the National Interagency Coordination Center, since the beginning of the year, more than 3 million acres had been burned in the state by over 500 fires by August 31. Monthly streamflow was mostly near to above normal with a few below-normal streams scattered about the state.

Drought in Alaska ended during August with only a few areas of abnormal dryness lingering in the eastern interior region on the August 30th USDM map.

Puerto Rico and U.S. Virgin Islands

August 2022 was wetter than normal across St. Charles and western and northern portions of Puerto Rico (PR); it was drier than normal in southern and eastern parts of PR and the rest of the U.S. Virgin Islands (USVI). The last 2 months had a mixed precipitation anomaly pattern, with wetter-than-normal conditions dominating. Drier-than-normal conditions dominated across the USVI starting at the 3-month time scale and in PR at the 4-month time scale. In the USVI, Rohlsen Airport on St. Croix had the fifth driest September-August in the 1951-2022 record. The drier-than-normal conditions extended into the longer time scales (radar-based precipitation anomaly estimates for the last 1, 2, 3, 6, 8, 11, 12 months) (low elevation station precipitation maps for the last 1, 2, 3, 4, 5, 6, 8, 9, 11, 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 northwestern coasts into the interior southeast portions 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 showed some areas of lingering vegetative stress (VHI for PR and USVI, drought risk for PR and USVI, stressed vegetation for PR and USVI). Monthly streamflow on PR was below normal at several gauges in the east and a few in the south. In the USVI, groundwater during August continued to steadily decline on St. John, rose then leveled off on St. Thomas, and fluctuated around a nadir on St. Croix. The groundwater level on St. Thomas set a new record low value (in the 2016-2022 record) early in August before rising later in the month. The groundwater level on St. Croix also set a new record low value, compared to the 2016-2022 record, before rising slightly at the end of the month. The August groundwater level on St. John was at the lowest level since November 2016. According to drought impact information summarized by the National Integrated Drought Information System (NIDIS):

  • Two major reservoirs (La Plata and Toa Vaca) on PR remain at "operational adjustment" levels, which is a level of concern but not low enough for rationing. The south and north coasts, as well as the southeastern interior, show extreme levels of crop stress and poor root-level saturation conditions.
  • In the USVI, ponds and soils continue to remain dry, with wells remaining at low levels. Farmers are purchasing water and implementing water conservation measures. On July 25, President Biden approved an Emergency Declaration for the USVI to supplement the territory's response efforts to the emergency conditions resulting from a water shortage and the health impacts from an unprecedented sargassum seagrass influx that began on July 15.

Drought contracted on PR. Moderate to severe drought covered 47.8 percent of the island at the end of July, but decreased to 28.8 percent by the end of August. As of August 30, PR has been in drought for a record 89 consecutive weeks. In the USVI, at the end of August, extreme drought continued on St. John and severe drought continued on St. Thomas and St. Croix.

CONUS State Precipitation Ranks

August 2022 was drier than normal across the central to northern Plains, much of the Pacific Northwest and immediate West Coast, much of the coastal Northeast, and parts of the rest of the Atlantic coast. Record dryness occurred locally in parts of the central Plains and Pacific Northwest. Thirteen states had a precipitation rank in the driest third of the 128-year historical record for August, including two in the top ten driest category — Nebraska (second driest) and Kansas (seventh driest).

This summer (June-August 2022) was drier than normal across much of the Plains to Mississippi Valley, parts of southern to central California, much of the Northeast, and parts of the Mid-Atlantic to Southeast. Record dryness occurred locally in a few parts of the Plains and Northeast. Nineteen states had a precipitation rank in the driest third of the 1895-2022 record for June-August, including three in the top ten driest category — Nebraska (third driest), New Jersey (sixth driest), and Massachusetts (tenth driest).

March-August 2022 was drier than normal across much of the Plains to Mid-Mississippi Valley, from California to the Great Basin, much of the Northeast, and parts of the Ohio Valley, Tennessee Valley, and Mid-Atlantic to Southeast. Sixteen states had a precipitation rank in the driest third of the historical record for March-August, including two in the top ten driest category — Nebraska (ninth driest) and Massachusetts (tenth driest) — and one that was close (Rhode Island at 12th driest).

The year to date (January-August 2022) was drier than normal across much of the West and Plains to Mid-Mississippi Valley, and parts of the Great Lakes and Atlantic Coast. Record dryness occurred locally in the West and Plains. Eighteen states had a precipitation rank in the driest third of the historical record for January-August, including three in the top ten driest category — California (driest on record), Nebraska (fifth driest), and Nevada (seventh driest) — plus two that were close (Texas and Utah, both 11th driest).

The last 12 months (September 2021-August 2022) was drier than normal across much of the West, Plains, and Mid-Atlantic coast, and in parts of the Mississippi Valley and Northeast. Record dryness occurred locally in the central Plains. Nineteen states had a precipitation rank in the driest third of the historical record for September-August, including two in the top ten driest category — Texas (sixth driest) and Nebraska (ninth driest) — plus one that was close (North Carolina at 11th driest).

Agricultural Belts

During August 2022, the Primary Corn and Soybean agricultural belt was generally warmer- and drier-than-normal to the northwest and near to cooler- and wetter-than-normal to the southeast. The month ranked as the 54th wettest and 46th warmest August, regionwide, in the 1895-2022 record.

March marks the beginning of the growing season for the Primary Corn and Soybean belt. March-August 2022 was generally had near normal temperatures and near to below-normal precipitation to the northwest and warmer-than-normal temperatures and near to above-normal precipitation in southeast areas. The period ranked as the 31st warmest and 56th wettest March-August, regionwide, on record.

According to the U.S. Department of Agriculture (USDA), as of August 30, 2022, drought affected approximately 51 percent of barley production, 28 percent of corn production, 47 percent of cotton production, 41 percent of rice production, 75 percent of sorghum production, 21 percent of soybean production, 20 percent of spring wheat production, 53 percent of winter wheat production, 41 percent of hay acreage, 56 percent of the cattle inventory, 44 percent of the milk cow inventory, and 57 percent of the sheep inventory. Based on August 28 USDA statistics, 19 percent of the corn crop, 13 percent of the soybean crop, 6 percent of the spring wheat crop, and 46 percent of the nation's pasture and rangeland were in poor to very poor condition, and 48 percent of the nation's topsoil and 49 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:

Statewide topsoil moisture, subsoil moisture, pasture and rangeland condition, and crop 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), August 2022 was drier-than-normal in the Marianas, southern RMI, and western, central, and southern FSM. It was near to wetter than normal in Palau, 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 Ulithi, Lukunor, and Kapingamarangi (FSM), and Jaluit and Wotje (RMI). August 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 August 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:

  • Guam: August 2022 precipitation 9.15 inches, August normal mean 17.15 inches, August normal median 14.74 inches
  • Saipan: August 2022 precipitation 10.55 inches, August normal mean 12.15 inches, August normal median 13.13 inches
  • Yap: August 2022 precipitation 9.57 inches, August normal mean 15.46 inches, August normal median 14.82 inches
  • Chuuk: August 2022 precipitation 8.98 inches, August normal mean 13.48 inches, August normal median 12.86 inches
  • Majuro: August 2022 precipitation 8.65 inches, August normal mean 11.42 inches, August normal median 11.69 inches

In the table below, the station identified as Koror is Palau International Airport (Airai).

Pacific Island Percent of 1981-2010 Normal Median Precipitation
Station Name Sep
2021
Oct
2021
Nov
2021
Dec
2021
Jan
2022
Feb
2022
Mar
2022
Apr
2022
May
2022
Jun
2022
Jul
2022
Aug
2022
Sep-
Aug
Chuuk143%138%112%149%39%39%166%138%176%68%107%70%109%
Guam NAS92%233%134%87%146%42%110%187%69%79%135%62%98%
Kapingamarangi40%30%29%148%94%131%58%66%10%25%61%51%53%
Koror164%233%70%155%113%124%156%303%203%81%72%119%128%
Kosrae107%129%122%160%74%77%216%195%132%139%169%117%116%
Kwajalein105%98%128%56%40%244%471%156%196%141%94%132%124%
Lukonor94%64%145%152%142%58%133%125%88%62%66%32%81%
Majuro111%119%130%77%61%128%298%255%66%71%96%74%116%
Pago Pago51%47%124%61%115%150%51%58%96%110%166%121%82%
Pohnpei105%95%174%96%76%182%211%157%112%122%173%138%132%
Saipan85%100%138%141%123%63%265%204%76%106%159%80%111%
Yap93%107%64%145%150%123%159%254%153%83%110%65%107%
Pacific Island Precipitation (Inches)
Station Name Sep
2021
Oct
2021
Nov
2021
Dec
2021
Jan
2022
Feb
2022
Mar
2022
Apr
2022
May
2022
Jun
2022
Jul
2022
Aug
2022
Sep-
Aug
Chuuk16.70"15.86"11.89"16.79"3.93"2.86"13.83"17.19"19.87"7.93"12.86"8.98"148.69"
Guam NAS11.61"26.68"9.87"4.47"5.84"1.28"2.28"4.74"2.35"4.88"13.71"9.15"96.86"
Kapingamarangi3.98"2.46"2.66"14.57"8.58"12.19"6.62"8.97"1.19"3.40"8.60"4.17"77.39"
Koror19.33"27.58"7.95"17.35"11.49"10.64"11.57"22.21"24.06"14.19"13.31"16.00"195.68"
Kosrae15.27"14.15"16.81"25.70"12.33"9.93"34.72"34.09"23.42"20.39"25.14"16.69"248.64"
Kwajalein11.30"10.97"14.47"3.74"1.25"6.45"11.07"8.21"13.17"9.78"9.23"12.81"112.45"
Lukonor9.50"7.25"13.20"17.10"11.94"5.16"12.28"14.14"10.27"7.19"10.52"4.55"123.1"
Majuro12.41"15.12"17.42"8.76"4.73"8.79"19.61"24.02"6.72"7.78"10.70"8.65"144.71"
Pago Pago3.33"4.38"12.58"7.83"15.39"17.94"5.50"5.42"9.32"5.84"9.23"6.53"103.29"
Pohnpei13.18"14.57"25.82"15.49"9.98"17.42"27.81"28.86"22.32"18.02"26.66"19.69"239.82"
Saipan8.62"10.63"7.76"5.41"3.12"1.62"5.01"5.36"1.81"3.84"14.16"10.55"77.89"
Yap12.55"13.00"5.68"12.31"9.57"6.36"7.23"14.28"12.04"10.04"16.54"9.57"129.17"
Pacific Island 1981-2010 Normal Median Precipitation (Inches)
Station Name Sep
2021
Oct
2021
Nov
2021
Dec
2021
Jan
2022
Feb
2022
Mar
2022
Apr
2022
May
2022
Jun
2022
Jul
2022
Aug
2022
Sep-
Aug
Chuuk11.71"11.51"10.61"11.25"10.10"7.25"8.32"12.47"11.30"11.66"11.98"12.86"136.77"
Guam NAS12.66"11.44"7.38"5.11"4.01"3.03"2.07"2.53"3.40"6.18"10.14"14.74"99.09"
Kapingamarangi9.93"8.19"9.27"9.84"9.15"9.27"11.43"13.64"12.08"13.78"14.15"8.13"145.85"
Koror11.77"11.84"11.39"11.16"10.18"8.56"7.44"7.32"11.83"17.48"18.53"13.50"152.90"
Kosrae14.22"10.94"13.83"16.11"16.67"12.93"16.06"17.51"17.75"14.64"14.91"14.22"213.87"
Kwajalein10.74"11.18"11.28"6.66"3.16"2.64"2.35"5.26"6.72"6.93"9.87"9.74"90.41"
Lukonor10.15"11.32"9.08"11.27"8.41"8.93"9.26"11.31"11.69"11.65"15.93"14.04"151.36"
Majuro11.17"12.73"13.44"11.39"7.74"6.88"6.58"9.42"10.11"11.01"11.17"11.69"125.25"
Pago Pago6.53"9.26"10.14"12.84"13.34"12.00"10.68"9.39"9.66"5.33"5.55"5.38"125.57"
Pohnpei12.55"15.27"14.83"16.08"13.18"9.55"13.17"18.41"19.96"14.81"15.43"14.26"182.36"
Saipan10.09"10.62"5.61"3.85"2.53"2.59"1.89"2.63"2.38"3.62"8.91"13.13"70.25"
Yap13.50"12.18"8.83"8.51"6.39"5.19"4.56"5.63"7.85"12.04"15.08"14.82"120.31"

As measured by percent of normal precipitation, Kapingamarangi and Lukunor were drier than normal in the short term (August and the last 3 months [June-August 2022]) and long term (year to date [January-August 2022] and last 12 months [September 2021-August 2022]). Guam was drier than normal in the short-term and for the year to date, and near normal for the last 12 months. Chuuk, Majuro, and Yap were drier than normal in the short-term and near to wetter than normal in the long-term. Pago Pago was drier than normal in the long term but wetter than normal in the short term. Airai and Saipan were drier than normal for one of the short-term periods and wetter than normal for the other 3 time periods. Kosrae, Kwajalein, and Pohnpei were 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 August 2022 was below normal across the main islands. It was drier than normal at the 4-month time scale, mostly wetter than normal at 11 months, with a mixed anomaly pattern at the intervening time scales and longer time scales (percent of normal precipitation maps for the last 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 24, 36, 48, 60 months).

Based on percent of normal average (instead of normal median values), in the Marshall Islands, August had a mixed precipitation anomaly pattern. The pattern was mixed for the last 2 to 5 months with wetter-than-normal conditions dominating. At the 6- to 12-month time scales, all of the main islands were wetter than normal. Longer time scales had a mixed anomaly pattern (percent of normal precipitation maps for the last 1, 2, 3, 4, 5, 6, 8, 9, 11, 12, 24, 36, 48, 60 months).

According to the August 31st USDM produced for the USAPI, moderate drought continued 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 August (on August 20) that noted that water levels for both private and public water tanks on Kapingamarangi were around 50% of capacity.

The reservoir level on Majuro began the month at around 22 million gallons of water, then fluctuated up and down before settling down and ending the month at about 23.3 million gallons. The maximum was 24.6 million and minimum 21.5 million gallons. These values are 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 minimum 21.5 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.

August had a mix of wet and dry precipitation ranks across the USAPI. Record dryness was still occurring at Kapingamarangi, and developed at Lukunor, at some time scales:

  • Kapingamarangi: 7th driest August (in a 32-year record), but driest May-August, April-August, & March-August; 2nd or 3rd driest rank for all other longer time periods (February-August through September-August).
  • Lukunor: driest August, July-August, June-August, & May-August (26 years); 2nd driest April-August.
  • Ulithi: 2nd driest August (40 years), July-August, & June-August (38 years); 3rd driest May-August (38 years).
  • Jaluit: 6th driest May-August (38 years) & 8th driest June-August (38 years).
  • Majuro: 5th driest May-August (68 years) & 8th driest June-August (69 years).
  • Chuuk: 8th driest August (72 years) & 6th driest June-August (71 years).
  • Yap: 11th driest August (72 years).
  • Guam: 11th driest August (66 years).
  • Pago Pago: 26th wettest August (57 years of data), but 8th driest September-August.

At the wet end of the scale, Mili had the second wettest August and wettest July-August & April-August thru September-August. Ailinglaplap had the wettest March-August (38 years) and September-August.

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 August 2022, March-August 2022 (last 6 months), and September 2021-August 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.

August 2022 USAPI Precipitation Ranks (1 = driest)
StationAugust 2022Mar-Aug 2022Sep 2021-Aug 2022Period of Record
RankYearsRankYearsRankYears
Ailinglaplap3338383836361981-2022
Airai4571687070701951-2022
Chuuk872447145711951-2022
Fananu--6--3--32003-2022
Guam1166196633651957-2022
Jaluit1539273819361981-2022
Kapingamarangi7321253201962-2022
Kosrae3454424427341954-2022
Kwajalein5571587054701952-2022
Lukunor1265269251981-2022
Majuro1469536849681954-2022
Mili3738373734341981-2022
Nukuoro1639353823371981-2022
Pago Pago325713568561966-2022
Pingelap3038363727341981-2022
Pohnpei6172697169711951-2022
Saipan1942384128331981-2022
Ulithi240283730341981-2022
Utirik--16--7--41985-2020
Woleai3041313327281968-2022
Wotje2239333825351981-2022
Yap1172507139711951-2022
Map of USAPIAugust 2022 Precipitation (Inches)
Map of USAPI August 2022 Percent of Normal Precipitation
Map of USAPI June 2022-August 2022 Percent of Normal Precipitation
Map of USAPI January-August 2022 Percent of Normal Precipitation
Map of USAPI September 2021-August 2022 Percent of Normal Precipitation

SPI values for seven time periods for Pacific Islands, computed by the Honolulu NWS office.

SPI values for seven time periods for Pacific Islands

NOAA Regional Climate Centers

More information, provided by the NOAA Regional Climate Centers and others, can be found below.

Southeast

As noted by the Southeast Regional Climate Center, after several months of mostly above-average temperatures across the Southeast, temperatures in August were below average across nearly two-thirds of the region. Monthly precipitation totals were above average across much of the Southeast region in August, but below average across northern portions of Alabama and Georgia, interior portions of the Carolinas, eastern portions of North Carolina and Virginia, and southern Florida, where monthly precipitation was less than 50 percent of normal in many places. Raleigh-Durham International Airport recorded just 0.91 inch (23 mm) of precipitation, which tied its second driest August on record (since 1887). Vero Beach, FL recorded its third driest August on record (since 1943) with 1.51 inches (38 mm) of precipitation (20 percent of normal). Many other locations in south Florida (e.g., Tampa, Naples, West Palm Beach, Miami, Key West) recorded between 25 and 50 percent of normal precipitation for the month.

Given the prodigious amount precipitation in many areas, drought conditions improved for the second straight month across a large portion of the Southeast. The greatest improvements were observed across the state of Georgia, which started the month with 44 percent of the state in at least abnormally dry (D0) conditions but ended with virtually the entire state free of any drought designation. The small areas of moderate drought (D1) in northern Alabama and eastern portions of North Carolina and Virginia seen at the end of July were mostly alleviated by the end of August, while some abnormally dry conditions remained. Drought conditions were also ameliorated across interior and eastern portions of Puerto Rico, though moderate and severe (D2) drought persisted across the northern and southern ends of the island. Severe and extreme (D3) drought also persisted across the U.S. Virgin Islands. There were some locations in the Southeast where drought conditions developed or worsened by the end of August. Small pockets of moderate drought emerged along the I-85 corridor in Upstate South Carolina, extreme eastern Virginia, and along Florida's Space Coast. Abnormally dry conditions also emerged across a large portion of southeast Florida, which has been unseasonably warm and dry over the past two months. By the end of August, only about 1 percent of the Southeast region was in moderate drought (down from about 3 percent at the end of July) and 12 percent of the region was classified as abnormally dry (down from about 27 percent at the end of July). The percent of the region free of any drought designation increased from 70 percent at the end of July to over 87 percent at the end of August.

South

As explained by the Southern Regional Climate Center, August 2022 ended up as a run-of-the-mill month for temperatures in the Southern region, starting warm and finishing mild. But the month capped a summer that was third warmest on record for the region.

The Southern region had its tenth wettest August on record, with a region-average rainfall of 4.97 inches. The first half of August featured drought; the second half, flood. Flood-producing rains during the last half of August made a serious dent in drought conditions across most of the region. Drought intensity in the Southern region, as measured by the Drought Severity and Coverage Index (DSCI), peaked on August 9 at 286, meaning that severe drought was the norm. The last time the DSCI had been so high was in November 2011. By the end of the month, the DSCI was down to 193, implying about a one-category across-the-board improvement. Only Oklahoma missed out, with about half the state still in extreme drought. The rainfall was beneficial to farmers that still had viable crops, ranchers who may get another hay cutting this fall, and most water suppliers.

Midwest

As described by the Midwest Regional Climate Center, the average temperature for August in the Midwest was 71.5 degrees F (21.9 degrees C), which was 0.6 degrees F (0.3 degrees C) above the 1991-2020 normal. August precipitation was 4.34 inches (110 mm) for the Midwest, which was 0.67 inch (17 mm) above normal, or 118 percent of normal. Summer (June-August) precipitation for the Midwest totaled 11.39 inches (289 mm), which was 0.92 inch (23.4 mm) below normal. Generally, the western areas had a dry summer while extreme wetness was reported across the southern areas.

Increased widespread rainfall and moderated temperatures brought drought relief to many locations, but not all, across the Midwest throughout August. By month's end, dryness and drought affected 28 percent of the region, down from 39 percent coverage at the start of August. Missouri, southern Illinois, and western Kentucky had rapid drought recovery whereas conditions worsened in Iowa and across the upper Midwest. Looking across summer (June-August), dryness and drought exhibited rapid onset and rapid recovery. Dry conditions affected just 9 percent of the Midwest to start summer, and conditions peaked weeks later with 50 percent of the region affected. As precipitation returned for some locations, summer ended with dryness or drought affecting 28 percent of the Midwest.

Northeast

As summarized by the Northeast Regional Climate Center, a record-hot August closed out a warm summer, with the Northeast experiencing precipitation extremes ranging from intensifying drought to record wetness and flash flooding.

The Northeast had its fifth hottest August since records began in 1895 with an average temperature of 71.1 degrees F, 2.4 degrees F above normal. This August was the hottest August on record for Connecticut, Massachusetts, New Hampshire, New Jersey, and Rhode Island. The Northeast received 4.01 inches of precipitation, 100 percent of normal, during August. August precipitation for the 12 Northeast states ranged from 57 percent of normal in New Jersey to 144 percent of normal in West Virginia, with 10 states landing on the dry side of normal. For summer, the Northeast picked up 11.40 inches of precipitation, 89 percent of normal. Summer precipitation for the 12 Northeast states ranged from 59 percent of normal in New Jersey to 122 percent of normal in West Virginia, with 10 states being drier than normal.

The USDM released on August 4 showed 5 percent of the Northeast in severe drought, 18 percent in moderate drought, and 26 percent as abnormally dry. Conditions deteriorated during August due to factors such as increasing precipitation deficits, low streamflow, below-normal groundwater levels, little soil moisture, above-normal temperatures, and impacts on water resources, wildfires, and agriculture. Extreme drought was introduced in southern New England, while severe drought expanded or was introduced in New England, southeastern New York, and New Jersey. Moderate drought and abnormal dryness also expanded in many parts of the Northeast. The main exceptions were West Virginia, western Maryland, and portions of Maine which received enough rainfall to help alleviate dryness. The USDM released on September 1 showed 2 percent of the Northeast in extreme drought, 9 percent in severe drought, 13 percent in moderate drought, and 35 percent as abnormally dry.

There were a multitude of impacts from the drought conditions. Multiple waterways including several in southern New Hampshire, southern New England, central Pennsylvania, and New Jersey observed record or near-record low streamflows. Less power was generated along a section of the Connecticut River due to reduced streamflow. Low water levels and above-normal temperatures on some waterways in New England stressed fish, affected recreational activities, and contributed to increased algae growth. As of August 29, 83 wells had run dry in Maine, where well drilling companies saw increased business. New Hampshire officials encouraged homeowners relying on well water to test their water quality as lower-than-normal water levels in wells could lead to an increased concentration of undesirable minerals. Water restrictions continued, and in some locations were enhanced, in numerous communities in New England and several in New York, Pennsylvania, and New Jersey. As of September 2, 104 New Hampshire water systems and nine municipalities had water restrictions in place, with most being mandatory. In an effort to conserve water, some Rhode Island state parks shut off their showers. Dry grass and shrubs increased fuels available to fires, with an enhanced fire risk and an uptick in fires in multiple states. For instance, Massachusetts saw over 100 wildfires in August while Maine saw more than 50 wildfires. In addition, fires burned deeper and were more difficult to extinguish. Drought conditions could affect the timing of fall foliage. Farmers continued to rely heavily on irrigation, increasing labor and costs of operation. In fact, one Massachusetts farmer estimated additional costs of up to $100,000 due to irrigation. Crop losses and reduced yields, dried up Christmas tree saplings, and stunted, drought-stressed crops were reported in parts of New England, New York, and Pennsylvania. Hay quality and yields were reduced in drought-stricken areas, with some farmers getting only one cutting of hay instead of three and some using supplemental feed, further increasing operational costs. In addition, some farmers hauled in water, adding additional costs. For some Massachusetts farmers, irrigation water supplies dried up or had water quality issues. Dry conditions in Maine stressed some bee hives, with reduced honey yields expected. Trees in southeastern Pennsylvania dropped leaves prematurely due to stress from hot, dry weather. Preliminary data from Rhode Island indicated a decrease in the mosquito population due to less standing water but an increase in the tick population due to increased humidity. In Massachusetts, there was an increase in wildlife sightings and bee activity as animals and insects sought water. Businesses such as amusement parks have benefited from the hot, dry weather.

High Plains

As summarized by the High Plains Regional Climate Center, the summer of 2022 ended much like it began, with hot and dry conditions throughout the region. The resulting drought from these conditions and their effects has finally become clear, with numerous impacts on agriculture, livestock, and water resources. Kansas and Nebraska have taken the brunt of the drought, with conditions being as bad as 2012 in some places.

Temperatures were above normal throughout not only August, but the entire summer. Numerous locations across the region ranked in the top 10 warmest Augusts and summers. The southwest monsoon brought beneficial precipitation to the western states. Outside of the monsoon in the west, precipitation was spotty at best in August. The majority of Kansas and Nebraska were well below-normal this past month, further exacerbating the dire drought situation in both states. Nebraska was particularly dry, with numerous locations ranking in the top 10 driest, both for August and for the entire summer.

The southwest monsoon brought drought relief to Colorado and parts of Wyoming, while the rest of the region continued the trend of dryness and above-normal temperatures. Overall, there was a 7 percent increase in moderate to exceptional (D1-D4) drought in August. After several months of being drought-free, D1 was re-introduced in North Dakota. After an entire summer of near-record heat and dry weather, extreme to exceptional (D3-D4) conditions have become entrenched across southwestern Nebraska and western Kansas. This has taken a significant toll on agriculture, with poor crop conditions and impacts on livestock. In the eastern parts of both states, drought conditions were introduced and slowly began to spread. On the other hand, an above-normal amount of precipitation due to the southwest monsoon improved drought conditions in Colorado with D1-D4 reduced by 33 percent compared to the beginning of the month. Elsewhere in the region, other improvements and degradation were observed.

Agricultural conditions have steadily deteriorated over the summer in Kansas and Nebraska, particularly in the western parts of both states. According to the USDA National Agricultural Statistics Service, corn that was rated poor to very poor reached 50 percent in Kansas and 34 percent in Nebraska. This marked a 17 and 12 percent increase since the end of July. Fields across western Kansas are being cut for silage or filed for crop insurance as a result of the poor conditions. Even drought-resistant sorghum was impacted, with over 50 percent of fields in both states rated as poor to very poor. Nearly 78 percent of pastures in Nebraska and 65 percent in Kansas are rated poor to very poor. With such poor grasses, farmers have struggled to find feed for their cattle, and feedlots in western Kansas have been importing silage from over 50 miles away.

West

As summarized by the Western Regional Climate Center, hot and dry conditions were persistent through August across the Pacific Northwest and northern Great Basin with many monthly mean temperature records broken. The Southwest monsoon remained active across Arizona and New Mexico with below-normal temperatures and above-normal precipitation. Several surges of monsoonal moisture pushed north and westward into the deserts of eastern California and western Nevada, bringing heavy rainfall and flash flooding.

Precipitation, although spotty, was above normal across much of Arizona, New Mexico, eastern California, and the Great Basin. A number of records were broken in the deserts of eastern California and western Nevada due to heavy rainfall driven by northward surges of monsoonal moisture. The Pacific Northwest saw below-normal precipitation with much of western Oregon and western Washington less than 25 percent of normal. Seattle, Washington recorded just 0.05 inch (1.3 millimeters) at five percent of normal coming in as the seventh driest August on record.

According to the USDM at the end of August, 68 percent of the West was in drought with 20 percent of the West in extreme (D3) or exceptional (D4) drought. Drought reductions of up to two categories were found in Arizona, southern Nevada, and southwest Utah. Drought expansion of up to two categories was found in southwest Montana. Overall drought coverage across the West was slightly lower at the end of August compared to the end of July.

Temperatures were near normal across Alaska except for southeast Alaska where temperatures were 2 to 3 degrees Fahrenheit above normal. Precipitation was well above normal in Southcentral and Southwest and below normal in parts of the central Interior.

Dry conditions continued for much of Hawaii. Honolulu logged 0.07 inch (1.8 millimeters) of precipitation, which equates to eight percent of normal for the ninth driest August on record, and Kahului recorded 0.06 inch (1.5 millimeters), 11 percent of normal, and also the ninth driest August on record. Drought conditions have worsened with the continued dryness and, according to the USDM, 94 percent of the state is in drought which is the greatest spatial extent of drought coverage since the Drought Monitor began in 2000.

Additional Resources


Citing This Report

NOAA National Centers for Environmental Information, Monthly Drought Report for August 2022, published online September 2022, retrieved on February 3, 2023 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/drought/202208.