Drought - January 2021
Issued 11 February 2021
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 28% of the contiguous United States as of the end of January 2021, about the same as last month. About 6% of the contiguous U.S. fell in the severely to extremely wet categories.
- About 39% of the contiguous U.S. fell in the moderate to extreme drought categories (based on the Palmer Drought Index) at the end of January
- 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 February 2, 2021, 45.77% of the contiguous U.S. (CONUS) (38.27% of the U.S. including Alaska, Hawaii, and Puerto Rico) was classified as experiencing moderate to exceptional (D1-D4) drought.
Detailed Drought Overview
The very active atmospheric circulation over North America during January 2021 consisted of several shortwave troughs and closed lows moving through the jet stream flow. These Pacific weather systems traversed a broad upper-level ridge over the West. The shortwave troughs and closed lows interacted with the ridge in a complicated dance which shifted the longwave trough/ridge pattern back and forth across the CONUS as the month wore on. When averaged across the month, the highly meridional day-to-day fluctuations averaged out to a pattern consisting of a ridge over the West and trough in the East, with a split flow creating a trough over the southwest border centered over Baja California. The monthly upper-level circulation anomalies were strong over the Pacific, Atlantic, and eastern Canada, but weak over the CONUS; the weak anomalies over the CONUS represented the frequent battle between short-wave troughs and short-wave ridges. The surface fronts and low pressure systems were mostly of Pacific origin moving in the westerly jet stream flow, although a few colder Canadian fronts were able to penetrate into the CONUS when stronger upper-level lows and troughs intensified east of the Rockies. The combination of predominantly Pacific air masses and upper-level ridging gave the CONUS warmer-than-normal monthly temperatures except in the Southwest where troughing was frequently dominant. The Pacific air masses were dried out as they crossed the coastal and Rocky mountain ranges, with Gulf of Mexico moisture becoming entrained once they reached the Plains. This resulted in a monthly precipitation anomaly pattern where the West was mostly drier than normal with some wetter-than-normal areas, the southern to central Plains and coastal Southeast were wetter than normal, and the northern Plains to Northeast, and much of the Deep South to Florida, were drier than normal.
As a result of these conditions, drought or abnormal dryness contracted in the Far West and parts of the Southwest, southern to central Plains, and Midwest. Drought or abnormal dryness expanded or intensified in parts of the interior West, northern Plains, Upper Midwest, and Deep South to Florida. Drought contraction exceeded expansion with the USDM-based national moderate-to-exceptional drought footprint across the CONUS falling from 49.0 percent at the end of December to 45.8 percent at the end of January (from 41.0 percent to 38.3 percent for the 50 States and Puerto Rico). According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 38.6 percent of the CONUS was in moderate to extreme drought at the end of January, a slight increase compared to the end of December.
Drought conditions at the end of January, as depicted on the February 2, 2021 USDM map, included the following core drought and abnormally dry areas:
- Moderate (D1) to extreme (D3) drought extended from the West Coast to Rocky Mountains and into the adjacent High Plains, with a large area of exceptional (D4) drought across the Southwest to southern High Plains. The percent area of the West experiencing moderate to exceptional drought, according to USDM statistics, increased from 78.6 percent at the end of December to 79.7 percent at the end of January largely due to drought expansion in Montana and Wyoming. The percent area of the West (from the Rockies to the West Coast) in moderate to extreme drought (based on the Palmer Drought Index) increased slightly to about 80.9 percent. Pacific weather systems brought above-normal rain and snow to parts of the West this month, improving streamflow, soil moisture, and mountain snowpack in parts of coastal California and the Pacific Northwest. But large parts of the West continued to have low mountain snowpack, streamflow, and groundwater levels, dry soils (based on GRACE, CPC Leaky Bucket, NLDAS, VIC, and SPoRT shallow layer and deep layer data), and some low reservoirs. And the beneficial precipitation in January was not enough to make up for deficits that have built up over the last several months to two or more years (SPI maps for the last 2, 3, 6, 9, 12, 24 months). Temperatures this month were well above normal in parts of Montana. Even though vegetation is dormant this time of year across much of the CONUS, the above-normal temperatures in eastern Montana resulted in above-normal evapotranspiration which could have contributed to additional drying of soils that were still above freezing and lacked a protective snow cover.
- Drought continued to expand in the northern Plains but contracted in the central and southern Plains. Moderate to exceptional drought covered most of the central to northern Plains at the end of January, increasing to 83.5 percent of the region, while moderate to exceptional drought contracted in the southern Plains to Lower Mississippi Valley to about 26.2 percent of the region. Soil moisture was quite low, especially in the western portions of the Plains (the "High Plains") and in the central and northern portions.
- In the Midwest, moderate to extreme drought continued in western Iowa, with areas of moderate drought in Minnesota and the Ohio Valley states.
- In the Northeast, moderate drought lingered in parts of northern New York and New England.
- In the Southeast, moderate drought developed in Alabama and abnormal dryness doubled in extent to 21.9 percent of the region.
- In Hawaii, moderate to extreme drought shrank to cover 11.8 percent of the state.
- In the U.S.-Affiliated Pacific Islands (USAPI), beneficial January rains improved exceptional drought to extreme drought in southern Micronesia at Kapingamarangi, but continued dry conditions resulted in moderate drought developing in the northern Marshall Islands at Kwajalein and Wotje and abnormal dryness developing in the Marianas at Rota and Saipan.
- Moderate drought expanded in northern parts of Puerto Rico and developed in the northern U.S. Virgin Islands (USVI) at Saint Thomas and Saint John.
- Abnormal dryness doubled in area to cover 19.4 percent of Alaska.
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 across much of the Northeast and central to northern Rockies and parts of the Great Lakes, Tennessee Valley, Gulf of Mexico coast, and Great Basin to coastal ranges in the West, expanding and intensifying long-term dry conditions in the West and Northeast, and contracting long-term wet conditions in parts of the Great Lakes and South (PHDI maps for January compared to December). Short-term wet conditions from the central Plains to Mid-Mississippi Valley expanded or intensified long-term wet conditions in that region.
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. Dry conditions dominate the northern and central Rockies to northern Plains at the 1- to 12-month time scales, from California to the High Plains at 3 to 12 months, and the Southwest at 24 months. Parts of the Pacific Northwest are dry at the 2- to 24-month time scales. The central Plains are dry at 6 to 12 months. Parts of the southern Plains have dry conditions at 3 to 24 months. Dryness covers much of the Great Lakes at the 1- to 3-month time scales and parts of the region at 6 months. Much of the Northeast is dry at 1 and 9 months, and parts of the region at 3, 6, and 12 months. Parts of the Gulf of Mexico coast and Lower Mississippi to Tennessee Valleys show dryness at 1 to 3 months. Wet conditions are evident across the central Plains and parts of the southern Plains at the 1- to 3-month time scales, the Great Lakes at 9 to 12 months, the Lower Mississippi Valley at 6 to 9 months, and the southern to mid-Atlantic coast at 1 to 12 months, and across most of the CONUS east of the Rockies at 24 months.
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.
With temperatures below freezing and vegetation dormant across a large part of the CONUS during the cold season, evapotranspiration is minimal and the SPEI and SPI maps show similar patterns of dryness and wetness. This was the case for January and the last 2 to 3 months. However, excessive heat in the Southwest during the warm season resulted in more extreme SPEI values than SPI values there for much of 2020 (SPEI vs. SPI maps for the last six months) (SPEI vs. SPI maps for the last 12 months) (SPEI vs. SPI maps for the last 24 months).
January 2021 was mostly warmer than normal across Hawaii with a mixed precipitation anomaly pattern. The precipitation anomaly pattern for the last 2 to 4 months was mixed but trending toward a predominantly drier-than-normal pattern. Precipitation was below normal across the state at 6 to 9 months, with a mixed anomaly pattern evident 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). Near to above-normal monthly streamflow dominated on many islands. A Drought Information Statement issued by the National Weather Service in Honolulu in mid-January indicated that poor vegetative health, agricultural and hydrological drought impacts were being experienced at that time. An observer in Maui County mentioned that numerous cattle and Axis deer have died in the area due to the lack of water and insufficient forage. Drought and abnormal dryness contracted across much of Hawaii, especially near the end of the month. The statewide moderate to extreme drought area shrank from 19.3 percent at the end of December to 11.8 percent by the end of January.
January was drier than normal in the central to eastern interior sections of Alaska, and wetter than normal across the southern coastal, southwestern, and panhandle regions. This precipitation anomaly pattern extended through time to the last 4 months. Dryness shifted to the central to western sections at the 6- to 9-month time scales, then to the southern coastal, Aleutian, and some northern sections by 12 months. At longer time scales, the precipitation anomaly pattern was mixed in the southern coastal areas and wetter than normal elsewhere (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 maps for the last 1, 4, and 12 months) (high elevation SNOTEL station precipitation anomaly maps for the last 1 and 4 months) (SNOTEL basin precipitation anomaly maps for the last 1, 4, and 12 months) (gridded precipitation percentile maps for the last 1 and 3 months) (climate division precipitation rank maps for the last 1, 3, 6, and 12 months) (Leaky Bucket model precipitation percentile map). January was warmer than normal across the state. The last 2 to 6 months were also warmer than normal across the state. At the 12-month time scale, parts of the panhandle were near to cooler than normal, but the rest of the state was warmer than normal (low elevation station temperature maps for the last 1, 2, 3, 4, 12 months) (gridded temperature percentile maps for the last 1 and 3 months) (climate division temperature rank maps for the last 1, 3, 6, 12 months) (Leaky Bucket model temperature percentile map). End-of-January snow pack was above normal in south coastal areas and below normal to the north toward the interior. Monthly streamflow (for those streams that were not frozen) was mostly near to above normal. Abnormal dryness continued in the northwest and expanded in the eastern interior sections, growing to 19.4 percent of the state on the February 2nd USDM map.
Puerto Rico and U.S. Virgin Islands
January 2021 and December-January were drier than normal across most of Puerto Rico (PR) and the the U.S. Virgin Islands (USVI). At the 3-month time scale, dryness was confined to the north central portions of PR and St. Croix in the USVI, but was more widespread across PR and the USVI at 4 to 6 months. The precipitation anomaly pattern across PR was mixed at longer time scales, becoming predominantly wetter than normal at 48 to 60 months, while drier-than-normal conditions dominated across the USVI at longer time scales (radar-based precipitation anomaly estimates for the last 1, 2, 3, 4, 6, 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 January).
Root zone analyses indicated that soil conditions were dry along the immediate southern and northwest coasts of PR. Monthly streamflow was mostly near to below normal across PR. Abnormal dryness and moderate drought covered about a fourth of PR (in the north central region) on the February 2nd USDM map, while on the USVI USDM map, St. Thomas and St. John had moderate drought while St. Croix was abnormally dry.
CONUS State Precipitation Ranks
January 2021 was drier than normal across much of the West, northern Plains, Great Lakes, and Northeast, and parts of the South. Over half (26) of the states in these regions had a precipitation rank in the driest third of the 127-year historical record for January, including Michigan, which ranked 12th driest, and New Jersey and Pennsylvania, which both ranked 13th driest.
November 2020-January 2021 was drier than normal across most of the CONUS, especially the West, northern and central Plains, and Great Lakes to Gulf of Mexico coast. Record dryness occurred in parts of the northern Plains. Twenty-two states in these regions had a precipitation rank in the driest third of the 127-year historical record for November-January, including two in the top ten driest category — North Dakota (which ranked fourth driest) and Wyoming (tenth driest). At 12th driest, Tennessee almost made the top ten driest category.
The unusual dryness in the northern Plains was accompanied by unusually warm temperatures for this time of year. Both North and South Dakota had the warmest November-January on record, with all of the Plains and Mississippi Valley states from Montana to Wisconsin to Oklahoma ranking in the top ten warmest category.
August 2020-January 2021 was drier than normal across most of the CONUS from the West Coast to Great Plains and parts of the Midwest, Northeast, and Lower Mississippi Valley, with record dryness occurring in parts of the Southwest and central to northern Plains. Nineteen states in these regions had a precipitation rank in the driest third of the 1895-2021 record, including nine in the top ten driest category — Arizona, Nevada, and Utah (each ranking driest on record); New Mexico and Wyoming (each ranking second driest); Colorado, Nebraska, and North Dakota (each ranking third driest); and California (tenth driest). In addition, all of these top ten driest states also had a top ten warmest August-January, including California at record warmest.
February 2020-January 2021 had a similar precipitation anomaly pattern, with drier than normal conditions across most of the CONUS from the West Coast to Great Plains and parts of the Midwest and Northeast, and record dryness occurring in parts of the Southwest and Great Basin. Nineteen states in these regions had a precipitation rank in the driest third of the historical record, including eight in the top ten driest category — Utah (ranking driest on record); Colorado, New Mexico, and Wyoming (each ranking second driest); Nevada (third driest); Arizona (fourth driest); California (seventh driest); and North Dakota (eighth driest). In addition, all of these top ten driest states (except Wyoming) also had a top ten warmest February-January, including Arizona and New Mexico at second warmest.
During January 2021, the Primary Hard Red Winter Wheat agricultural belt was mostly wetter and warmer than normal. The month ranked as the 24th wettest and 22nd warmest January, regionwide, in the 1895-2021 record.
October marks the beginning of the growing season for the Primary Hard Red Winter Wheat belt. October 2020-January 2021 was mostly drier and warmer than normal, with a wet streak across the middle. The period ranked as the 54th driest and 12th warmest October-January, regionwide, in the 1895-2021 record.
As of February 2, drought affected approximately 74 percent of spring wheat production, 59 percent of sorghum production, 51 percent of the sheep inventory, 48 percent of barley production, 45 percent of the cattle inventory, 37 percent of the milk cow inventory, 35 percent of hay acreage, 34 percent of cotton production, 32 percent of corn production, 31 percent of winter wheat production, 26 percent of soybean production, 22 percent of rice production, and 10 percent of peanut production.
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), January 2021 was drier-than-normal in the southern FSM (Kapingamarangi), northern RMI (Kwajalein), and northern Marianas (Saipan). It was near to wetter than normal at Pago Pago (American Samoa) and Guam, in the Republic of Palau, and in the rest of the RMI 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 Kapingamarangi (in southern FSM), due mostly to the ongoing La Niña, and in northern portions of the Marianas, RMI, and FSM, due mostly to the seasonal shift in the trade wind flow and Inter-Tropical Convergence Zone (ITCZ). January precipitation was above the monthly minimums at the rest of the USAPI stations in Micronesia and American Samoa. The 4- and 8-inch thresholds are important because, if monthly precipitation falls below the threshold, then water shortages or drought become a concern.
As measured by percent of normal precipitation, Kapingamarangi was drier than normal in the short term (January and the last 3 months [November 2020-January 2021]) and long term (last 12 months [ February 2020-January 2021]). Kwajalein was drier than normal in the short term and near normal in the long term. Guam and Lukonor were near to wetter than normal in the short term and drier than normal in the long term. Saipan was drier than normal for January and the last 12 months, but near normal for the last 3 months. Chuuk, Koror, Kosrae, Majuro, Pago Pago, Pohnpei, and Yap were near to wetter than normal at all 3 time scales.
Based on percent of normal average (instead of normal median values), in the Marianas Islands, precipitation during January was wetter than normal at Guam but drier than normal on the islands to the north. A mixed precipitation anomaly pattern was evident at 2 to 6 months, with drier conditions frequently in the north. At the 7- to 12-month time scales, generally Guam was wetter than normal and the islands to the north (Commonwealth of the Northern Mariana Islands) (CNMI) were drier than normal. Drier-than-normal conditions mostly 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). In the Marshall Islands, January was drier than normal in the north (Kwajalein and Wotje) and southwest (Jaluit) and wetter-than-normal in between (Ailinglaplap, Majuro, and Mili). The north (Kwajalein) and southwest (Jaluit) dry pattern, with wet conditions elsewhere, generally persisted at the 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 January 31st USDM produced for the USAPI, conditions at Kapingamarangi (southern FSM)improved to extreme drought (D3), moderate drought (D1) developed in the northern Marshalls (Kwajalein and Wotje), and abnormal dryness (D0) developed in the CNMI (Rota and Saipan). The rest of the stations in Micronesia, and Tutuila in American Samoa, were free of drought and abnormal dryness. Storage in the Majuro reservoir dipped below the 80 percent of maximum threshold for concern on several days during the month, but was above that threshold at the end of the month, ending January at about 29.0 million gallons, which is 81 percent of maximum. The National Weather Service office in Guam issued three Drought Information Statements for the drought in January (on January 8 and 22) and early February discussing the conditions in the USAPI. Reports from Kapingamarangi indicate that all six 250-gallon reserve water catchment tanks had filled from the recent rains and the island was utilizing a large concrete water tank with water around a fourth capacity. Vegetation has turned much greener but was still recovering from meager rainfall since the end of July 2020; the rainfall was not enough to replenish the dried up taro patches. Breadfruit, a major staple food, continued to fall from trees prematurely. Reports out of the RMI indicate that water catchments on some of the northern islands were getting low and at least one of the northern atolls has been rationing water. A few low-impact fires have developed on Guam.
The last one to 12 months have been especially dry at some of the islands in Micronesia (based on monthly and seasonal precipitation ranks) and the last 6 to 12 months have been dry at others. January 2021 was the seventh driest January in a 31-year record at Kapingamarangi. The seven time periods from February-January through August-January were the driest on record at the station, September-January through November-January were the third driest, and December-January was fourth driest. Saipan had the 17th driest January out of a 41-year record, but February-January was second driest and March-January through June-January ranked third or fourth driest. Jaluit ranked sixth driest out of 38 years for January and sixth driest out of 35 years for June-January. Kwajalein had the seventh driest December-January out of a 69-year record.
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 January 2021, August 2020-January 2021 (last 6 months), and February 2020-January 2021 (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||January 2021||Aug 2020-Jan 2021||Feb 2020-Jan 2021||Period of Record|
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 were near average to above average across much of the Southeast region and Puerto Rico for the month of January, and monthly precipitation was variable across the region with a few wet and dry extremes recorded. The driest locations were found across Florida, Alabama, northern Georgia, northern Virginia, and Puerto Rico. Monthly precipitation totals ranged from 50 to less than 5 percent of normal across these locations. Melbourne, FL (1937-2021; 2nd driest) received only 0.04 inch (1 mm) of precipitation, which was over 2 inches (51 mm) below normal for the month. St. Thomas, USVI (1953-2021) reported its 3rd driest January on record with only 0.75 inch (19 mm) of precipitation, and Roosevelt Roads, PR (1942-2021) had its 7th driest January observing only 1.27 inches (32 mm) of precipitation. In contrast, the wettest locations were located across southern Georgia, central South Carolina, and eastern North Carolina. Precipitation totals ranged from 150 to 300 percent of normal.
Drought slightly intensified for Alabama and Puerto Rico, and abnormally dry conditions (D0) increased in coverage across portions of Florida and Georgia in January. At the beginning of the month, pockets of abnormally dry conditions (D0) were found in Georgia, Alabama, Florida, South Carolina and northern Puerto Rico. By the end of the month, these pockets of dryness (D0) expanded with a small area of moderate drought (D1) developing in Alabama, as well as in northern Puerto Rico. Growers had to irrigate the groves, as dry conditions developed in the citrus growing region of Florida.
As explained by the Southern Regional Climate Center, temperatures and precipitation for the month of January varied spatially across the Southern region. Cooler-than-normal temperatures occurred in the west and warmer-than-normal temperatures in the north and east. Parts of southern Mississippi, southern Louisiana, and western and southeastern Texas received 50 percent or less of normal precipitation, while parts of southeastern and western Texas as well as southern Mississippi received 25 percent or less of normal precipitation. In contrast, parts of southwestern and northwestern Arkansas, northern, central, and western Oklahoma, and eastern, central, and northern Texas received 150 percent or more of normal precipitation, while parts of northeastern, western, and southeastern Oklahoma as well as central and eastern Texas received precipitation 200 percent or more of normal.
At the end of January, drought conditions improved and deteriorated across the Southern region. Exceptional drought conditions persisted across western and northwestern Texas, but the total area experiencing exceptional drought conditions was reduced in scale, with some areas eliminated. Extreme drought conditions persisted across parts of western, northwestern, and southern Texas as well as southwestern Oklahoma, with a slight increase in southern Texas. However, parts of central and western Texas as well as southwestern Oklahoma improved, with central Texas experiencing a substantial reduction while extreme drought conditions in far western Oklahoma were eliminated. Severe drought classifications developed in northwestern Mississippi, but the total area experiencing severe drought classifications decreased as conditions improved across northern, southern and central Texas as well as southwestern Oklahoma. Moderate drought classifications expanded or developed across southern Louisiana, while moderate drought conditions persisted across parts of Tennessee, Mississippi, Oklahoma, and Texas. However, moderate drought conditions were reduced or eliminated across parts of southern Oklahoma, southwestern Arkansas, southwestern Tennessee, and eastern, central, and southern Texas. There was a decrease in the overall area experiencing abnormally dry conditions, with conditions improving across southeastern Oklahoma, north-central Texas, northwestern Louisiana, northern Mississippi, and most of Arkansas. However, abnormally dry conditions increased across eastern Tennessee, northeastern and southeastern Louisiana, and eastern Mississippi.
As described by the Midwest Regional Climate Center, January temperatures were above normal across the entire Midwest and January precipitation varied considerably across the region, but the overall average was 1.40 inches (36 mm) which was 0.37 inch (9 mm) below normal. Dry conditions in the northern and eastern parts of the region offset wet conditions in the southwestern and southern parts of the region. Michigan recorded its 11th driest January on record (1895-2021). The lack of precipitation in the northern areas was also noticeable in the snow totals for that area.
Despite a drier-than-normal January in the Midwest, drought coverage decreased slightly with low water demand and well-placed precipitation. Overall, drought coverage dropped around 1.5 percent according to the January 28th USDM compared to the start of the month. Drought severity also slightly decreased in western Iowa. However, abnormally dry conditions increased across the Upper Midwest. All of Minnesota was either abnormally dry or in moderate drought at the end of the month, with most of northern Wisconsin also abnormally dry.
As explained by the Northeast Regional Climate Center, it was the 13th driest January on record for the Northeast with 2.03 inches (51.56 mm) of precipitation, 62 percent of normal. Precipitation for all 12 Northeast states ranged from 53 percent of normal in Pennsylvania to 75 percent of normal in West Virginia. Four states experienced one of their 20 driest Januarys on record: New Jersey and Pennsylvania, 13th driest; Maine, 16th driest; and Maryland, 17th driest. The Northeast's average temperature of 27.2 degrees F (-2.7 degrees C) was 3.1 degrees F (1.7 degrees C) above normal, with all twelve Northeast states warmer than normal.
The USDM from January 5 showed 4 percent of the Northeast in a moderate drought and 17 percent of the region as abnormally dry. These areas included portions of northern New England, New York, and Pennsylvania. There were only minor changes in conditions during January, with slight expansion of moderate drought and/or abnormal dryness in northeastern Vermont, northern New Hampshire, western Maine, and far northern New York but the easing of small areas of abnormal dryness in southern Maine, southeastern New Hampshire, and northwestern New York. Conditions were unchanged during January for the rest of the region. The USDM from January 26 showed 5 percent of the Northeast in a moderate drought and 16 percent of the region as abnormally dry.
As summarized by the High Plains Regional Climate Center, January was an eventful month for the High Plains region. In northern parts of the region, extreme "warmth" was a consistent feature, as temperatures were routinely much above normal. This resulted in monthly temperature departures of up to 15.0 degrees F (8.3 degrees C) above normal. A low or non-existent snowpack across the Plains portion of the region contributed to these departures. The relative warmth, along with dry conditions, led to an overall expansion of drought conditions in the Dakotas, which is rare in the winter. Meanwhile, heavy rain and snow in eastern parts of Kansas and Nebraska set new records and helped improve or alleviate drought conditions there. In western areas of the region, drought continued to be a prominent feature, with mountain snowpack below median for this time of the year — the Upper Missouri Basin mountain snowpack declined slightly this month.
Precipitation varied across the High Plains region this month, with some areas receiving record-breaking precipitation and others receiving little to none. Overall, much of the region received less than 75 percent of normal precipitation. Although not record-breaking for most locations, a few of the drier locations did have a top 10 driest January on record. For instance, with only 0.04 inch (1 mm) received this past month, Rapid City, SD had its 4th driest January on record (period of record 1942-present). While precipitation deficits do not build quickly in the winter, it is worth noting that longer-term deficits, coupled with above-normal temperatures and a low snowpack, have caused an increase in drought conditions along with concerns about fire risk and winter wheat condition.
There were several changes in drought conditions this month in the High Plains region, which is unusual for this time of the year. According to the USDM, the area experiencing drought (D1-D4) increased from approximately 82 percent to 86 percent since the end of last month. However, the area experiencing abnormal dryness and drought (D0-D4) decreased from 96 percent to 93 percent. With precipitation deficits mounting, a continuation of relatively warm, dry conditions led to the expansion of drought in several areas of the region this month. The largest changes occurred across the Northern Plains, where North Dakota had a 7 percent increase in drought coverage, while South Dakota had a 28 percent increase. Although there was an overall degradation, there was a notable improvement in North Dakota as the area of extreme drought (D3) that was introduced in the east-central part of the state in December was removed after a reassessment of the data. In other areas of the region, Wyoming had an overall increase in drought of 2 percent, with the most notable change occurring in the northeastern part of the state due to precipitation deficits, low snowpack, and poor soil moisture conditions. Meanwhile, drought decreased in Nebraska and Kansas by 5 percent and 10 percent, respectively, due to ample rain and snow in eastern areas of both states. The entire state of Colorado remained in drought, although there were slight improvements in some mountainous areas, as well as the southeastern part of the state.
As described by the Western Regional Climate Center, after a dry first half of the month across much of the region, a series of Pacific storm systems in late January delivered significant precipitation accumulations to areas of the West experiencing drought including portions of California, Nevada, and the Four Corners states. Along the central California coast, significant rainfall accumulations (7 to 20+ inches) were observed. Numerous mountain ranges received heavy snowfall including the Klamath Mountains, Sierra Nevada, San Francisco Peaks, White Mountains, San Juan Mountains, and the ranges/plateaus of southern Utah. In the Pacific Northwest, precipitation for the month was above normal (about 100-200+% of normal) across the coastal ranges of western Oregon, west-central Idaho, as well as western and northern portions of Washington state. In the Intermountain West, recent storms improved mountain snowpack conditions, but basin-level snow water equivalent (SWE) continued to lag behind normal levels across most of the region with the Four Corners states continuing to experience substantial longer-term (6 to 36 months) precipitation deficits. By the end of January, 80% of the West was experiencing drought (21% in D4-Exceptional Drought) according to the USDM, with the most severe drought centered on the Four Corners states and Nevada. In statewide reservoir conditions (January 1), below-average storage levels were observed in California, Colorado, Idaho, Nevada, New Mexico, and Oregon.
In the Southwest, drought-related conditions (snow drought, low soil moisture, stressed vegetation) in Arizona saw some modest improvement as beneficial rains and snow fell across the Sonoran Desert while moderate-to-heavy snowfall accumulations were observed in areas along the Mogollon Rim and Colorado Plateau including Flagstaff that observed a monthly snowfall total of 43.5 in (1105 mm; 11th snowiest January) and Prescott 18.1 in (460 mm; 10th snowiest January). The storms significantly boosted SWE levels (Jan 31) in the Little Colorado and Verde River basins to 80% of median (18% on Jan 1) and 124% of median (13% on Jan 1), respectively. Likewise, mountain snowpack conditions improved in other basins (Salt, Upper Gila, Mimbres, Upper Pecos) in the region, but substantial water year-to-date (WYTD) deficits remained.
In Alaska, above-normal temperatures prevailed across the state with the greatest positive anomalies observed in the Interior where Eagle recorded its 4th warmest (+14F departure) January on record. Precipitation for the month was below normal in the Interior and northern portions while areas of the Panhandle, Southwest, and coastal mountains of Southcentral observed above-normal precipitation. In the Interior, Fairbanks observed only 0.5 in (12.7 mm) of snow, breaking the record (dating back to 1966) for the lowest January snowfall total. In the Panhandle, Ketchikan logged its 4th wettest Nov to Jan period with 77.64 in (1972 mm).
In the Hawaiian Islands, drought conditions improved on Lanai, Maui, Molokai, and Oahu, according to the USDM. For January, select rainfall totals were as follows: Hilo Intl AP 17.47 in (444 mm; 189% of normal), Honolulu Intl AP 3.23 in (82 mm; 140% of normal), Kahului AP 3.72 in (94 mm; 130% of normal), Lihue AP 1.68 in (43 mm; 45% of normal), and Molokai AP 1.16 in (29 mm; 29% of normal).