Issued 13 March 2024

February 2024 Palmer Z-Index
U.S. Percent Area Wet or Dry January 1996 - February 2024
February 2024 /monitoring-content/sotc/drought/2024/02/il-p-reg011dv00elem01-02022024.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

The upper-level atmospheric circulation over North America during February 2024 was very active with several short-wave troughs and ridges migrating through a long-wave pattern that shifted from week to week. The highly meridional day-to-day circulation, when averaged over the month, resulted in a fairly flat zonal pattern, with the monthly circulation anomalies for this month flattening out the normal more-amplified long-wave ridge/trough pattern.

Cold fronts and low pressure systems associated with Pacific weather systems moving in the upper-level flow brought above-normal precipitation to much of the West and parts of the western Plains. But they were mostly dried out after crossing the Rockies. Those surface lows that tracked across the northern states were moisture-starved. Those that took a more southerly route were able to tap Gulf of Mexico and Atlantic moisture, but their monthly precipitation totals were above normal in only a few parts of the South, Southeast, and Appalachians. Most areas east of the Plains had a drier-than-normal month, especially in the Midwest and Northeast. Hundreds of wildfires broke out from the southern Plains to Southeast during February, fueled by low humidity and strong winds in western areas and low precipitation in recent months. While there were occasional cold outbreaks associated with some of the cold fronts, the overall circulation pattern directed warmer air northward, resulting in a warmer-than-normal month for most of the CONUS. This was especially the case for the Midwest and northern Plains, were several states had a record to near-record warm February. Only Florida and parts of the Southwest had a near- to cooler-than-normal month.

The above-normal precipitation in the Southwest, central Plains, and Lower Mississippi to Tennessee valleys contracted or reduced the intensity of drought and abnormal dryness compared to the end of January. But dry conditions in parts of the Pacific Northwest and much of the Plains, Midwest, and the Carolinas resulted in expansion or intensification of drought and abnormal dryness. A dry February led to expansion in Hawaii, while a wetter-than-normal month caused contraction in Puerto Rico. Drought contraction exceeded expansion with the USDM-based national moderate-to-exceptional drought footprint across the CONUS decreasing from 23.5% at the end of January to 21.6% at the end of February (from 19.7% to 18.1% for the 50 states and Puerto Rico).

According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 22.7% of the CONUS was in moderate to extreme drought at the end of February, which is more than the end of January.

D0-D4D1-D4D2-D4D3-D4D4

Drought conditions at the end of February, as depicted on the February 27, 2024 USDM map, included the following core drought and abnormally dry areas:

February 2024 /monitoring-content/sotc/drought/2024/02/20240227_usdm.png

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.

February 2024 Palmer Z-Index
February 2024 PHDI

Used together, the Palmer Z Index and PHDI maps show that short-term drought occurred in the Mississippi to Ohio Valleys, Great Lakes, coastal Washington, Carolinas, and part of the Rio Grande Valley, expanding or intensifying long-term drought, and in the Northeast, reducing areas of long-term wet conditions (PHDI maps for February compared to January). Short-term wet conditions occurred in California and part of Arizona, contracting or reducing the intensity of long-term drought.

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.

February 2024 SPI
January-February 2024 SPI
December 2023-February 2024 SPI
September 2023-February 2024 SPI

The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Dryness is quite severe across most of the Northeast at the 1-month time scale and is evident in northern New England at 2 months, but wet conditions dominate the Northeast at longer time scales. The Great Lakes, Ohio Valley, and most of the Mississippi Valley are dry at 1 month; the Upper Mississippi Valley is dry at 2 and 9-24 months; most of the Mississippi Valley is dry at 9-12 months; the Mid-Mississippi Valley is dry at 24 months; the Ohio Valley is dry 6-24 months; and parts of the Great Lakes are dry at 2-12 months. The Mid-Atlantic coast to the Carolinas is dry at the 1-month time scale, with dryness in the Carolina coast at 2- and 9- to 24-month time scales. Parts of the Pacific Northwest are dry at all time scales. Parts of the northern Plains are dry at 1-3 months and 9-24 months. Most of the Rio Grande Valley is dry at 9-24 months and parts are dry at 2-6 months. The central Gulf of Mexico coast is dry at 1 month and the western half of the Gulf coast is dry at 9-24 months. Parts to most of the Southwest (Four Corners states) are dry at 6-12 months. Wet conditions are evident in the West at all time scales; in the Northeast at 3-24 months; across much of the Plains at 2-6 months, the central Plains at 1 and 9-12 months, and parts of the northern Plains at 3 to 24 months; across parts of the Mississippi Valley to Appalachians at 2-3 months; along the Gulf of Mexico Coast at 2 to 3 months; along much of the East Coast at 3 months; and in parts of the Southeast at 3 to 24 months.

June 2023-February 2024 SPI
March 2023-February 2024 SPI
March 2022-February 2024 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, February marks the end of climatological winter, which is the season with the lowest sun angle and annual minimum evapotranspiration. During February 2024, temperatures were warmer than normal across much of the CONUS, especially between the Rockies and Appalachians, with record-warm temperatures in parts of the Midwest. At this time of year, the sun angle is increasing at a faster rate as the Spring Equinox approaches, so even though this is winter, evapotranspiration was unusually high due to the excessively warm temperatures. The unusually high temperatures/evapotranspiration combined with near-record low precipitation to produce SPEI values that were more extreme than the corresponding SPI values in the Mid-Mississippi Valley. Much warmer-than-normal temperatures and below-normal precipitation in the Northeast produced extreme SPEI values, but they were not more extreme than the corresponding SPI values. Unusually warm and dry conditions during the spring, summer, and fall of 2023 resulted in more extreme SPEI values than SPI values at the 6- to 12-month time scales, especially in the Southwest (Four Corners states) and Lower Mississippi Valley (SPEI maps for the last 1, 3, 6, 9, 11, 12 months) (SPI maps for the last 1, 3, 6, 9, 11, 12 months).

The SPEI for February was more extreme than the SPI for Iowa and Missouri, and record dry, while near-record dry SPEI and SPI values occurred for New Hampshire and Vermont:

  • 1-month SPEI for Missouri vs. 1-month SPI. The February 2024 SPEI was the driest value in the 1895-2024 record, while the SPI barely ranked in the top ten driest category.
  • 1-month SPEI for Iowa vs. 1-month SPI. The February 2024 SPEI tied as the driest on record, while the SPI ranked only in the top five driest category.
  • 1-month SPEI for New Hampshire vs. 1-month SPI. Both the SPEI and SPI ranked as the second driest on record.
  • 1-month SPEI for Vermont vs. 1-month SPI. Both the SPEI and SPI ranked as the third driest on record.

The last 1 to 6 years have been unusually warm across much of the CONUS, especially in the South and West (state temperature rank maps for the last 1, 2, 3, 4, 5 years). The last 1 to 2 years have been extremely dry in the southern Plains to Upper Mississippi Valley; the last 3 to 4 years have been quite dry in the West to Great Plains; and the last 5 years have been unusually dry across much of the West and southern Plains (state precipitation rank maps for the last 1, 2, 3, 4, 5 years). In the last 1 to 5 years, the SPEI is more extreme than the SPI in the Pacific Northwest but especially in the Southwest to Lower Mississippi Valley. In the western U.S., where drought has dominated for much of the last 20 years, the combination of excessive heat and dryness has resulted in more extreme SPEI values than SPI values in parts of the West for the last 2 to 6 years (SPEI maps for last 18, 24, 36, 48, 60, 72 months) (SPI maps for last 18, 24, 36, 48, 60, 72 months).

The 24-month SPEI for Louisiana is more extreme than the corresponding SPI, ranking second driest compared to the SPI which is only in the top 5 driest category.

Regional Discussion

Upper Mississippi River Basin

The Upper Mississippi River Basin was very dry during spring to fall last year. Above-normal precipitation during December 2023 and January 2024 helped lessen precipitation deficits. But dry conditions returned this month, with February 2024 ranking as the second driest February, basinwide, in the 1895-2024 record. January-February 2024 ranked as the 59th driest January-February, June 2023-February 2024 ranked 16th driest, and the last 12 months (March 2023-February 2024) ranked 14th driest. According to the USDM, 54.3% of the basin was in moderate to extreme drought at the end of February, which is more than the 37.5% at the end of January. Based on the Palmer Drought Index, 69.1% of the basin was in moderate to extreme drought at the end of February, which is more than the end of January. This is less than the peak last year of 78.0% and much less than the peak of 100% which occurred in the 1970s and several times in the 1930s.

Ohio River Basin

The Ohio River Basin was very dry last year during the spring and later in the year. Above-normal precipitation during January 2024 helped lessen precipitation deficits. But dry conditions returned this month, with February 2024 ranking as the 25th driest February, basinwide, on record. September 2023-February 2024 ranked 21st driest. Based on the Palmer Drought Index, 13.6% of the basin was in moderate to extreme drought at the end of February, which is more than the end of January. This is less than the peak last year of 42.4% and much less than the peak of 100% which occurred as recently as late 1999 and several times before then.

Rio Grande River Basin

During October 2023-February 2024, parts of the Rio Grande River Basin have been wetter than normal, parts drier than normal, and parts near normal. But very dry and hot conditions of summer and early fall last year created significant precipitation deficits and expanded drought. Basinwide, February 2024 ranked as the 62nd wettest (67th driest) February on record, but June 2023-February 2024 ranked as the 12th driest June-February and March 2023-February 2024 ranked as the 21st driest such 12-month period. According to the USDM, 85.2% of the basin was in moderate to exceptional drought at the end of February, which is more than the 80.8% at the end of January. Based on the Palmer Drought Index, 80.0% of the basin was in moderate to extreme drought at the end of February, which is the same as the end of January and less than the peak of 100% that occurred just last year and many times in the last 30 years, 1950s, and early 1900s.

Hawaii

February 2024 was drier than normal across most of the Hawaiian Islands. January-February had a mixed precipitation anomaly pattern, with drier conditions on Kauai, much of Oahu, and the windward side of the Big Island. Drier-than-normal conditions dominated at 3 to 8 months, with a mixed anomaly pattern dominating at 11 to 12 months (precipitation anomaly maps for the last 1, 2, 3, 5, 6, 8, 11, 12 months) (climate engine model percent of normal precipitation map for the last month).

Monthly streamflow was near normal across most of the main islands with some below-normal stream levels. Based on satellite analyses (stressed vegetation, drought stress, VHI), vegetation was stressed on parts of the Big Island and Maui.

Moderate drought continued on the Big Island during February, with the drought area increasing slightly from 9.2% at the end of January to about 10.3% of the state on the February 27, 2024 USDM map.

Alaska

February 2024 was drier than normal across the Alaska panhandle and eastern interior regions, with dryness extending into the Cook Inlet at the 2-month time scale. At 3 months, dry conditions extended into the Northwest Gulf region and to the northwest coast, but the panhandle was wetter than normal. Drier-than-normal conditions shifted to the Cook Inlet to Aleutian chain areas at 5- to 12-month time scales (low elevation station precipitation anomaly maps for the last 1, 2, 3, 5, 6, 11, 12 months) (high elevation SNOTEL station precipitation percentile maps for the last 1 and 5 months) (SNOTEL basin and station percent of normal precipitation maps for the last 1, 2, 3, 5, and 12 months) (climate division precipitation rank maps for the last 1, 2, 3, 6, and 12 months) (climate engine model percent of normal precipitation map for the last month) (Leaky Bucket model precipitation percentile map).

February and January-February temperatures were near to cooler than normal in the central to eastern parts of the state and northern Panhandle, and warmer than normal along to the west and north and also in the southern Panhandle. The December-February anomaly pattern was similar, except all of the panhandle was warmer than normal. Most of the state was warmer than normal at 5 to 6 months. At the 12-month time scale, it was warmer than normal across most of the state, but the central to Northwest Gulf regions had near-average temperatures when compared to the long-term (1925-2024) average. When compared to more recent (1991-2020) normals, cooler-than-normal temperatures were evident in the southwest third of the state with warmer-than-average temperatures to the east and north because of a pronounced warming trend in recent decades (low elevation station temperature anomaly maps for the last 1, 2, 3, 5, 12 months) (climate division temperature rank maps for the last 1, 2, 3, 6, and 12 months) (gridded temperature percentile maps for the last 1, 2, and 3 months) (Leaky Bucket model temperature percentile map).

Monthly streamflow was mostly near to below normal for those streams that aren't frozen. Snow covered the state, with snow water content (SWE) near to above normal in most of the state but below normal in part of the panhandle and in some southwest and northwest basins. Satellite observations of vegetative health (stressed vegetation, drought stress, VHI) in southern parts of the state revealed areas of stressed vegetation. Satellite-based or modeled observations of groundwater and soil moisture (GRACE root zone and GRACE surface soil moisture; SPoRT estimates of soil moisture at four depths [0-10 cm, 10-40 cm, 40-100 cm, 100-200 cm]; Leaky Bucket modeled soil moisture) suggested some dryness was occurring in parts of the south and northeast, but the ground is mostly frozen; a more accurate determination will be made once the ground thaws.

Alaska continued free of drought or abnormal dryness on the February 27, 2024 USDM map.

Puerto Rico and U.S. Virgin Islands

February 2024 was wetter than normal across Puerto Rico (PR) and the U.S. Virgin Islands (USVI). Drier-than-normal conditions were evident in northwest and eastern PR at the 2-month time scale and expanded to cover most of PR by the 5-month time scale. At the 12-month time scale, drier-than-normal conditions dominated the USVI and the northern two-thirds of PR as well as southwest PR (radar-based precipitation anomaly estimates for the last 1, 2, 3, 5, 6, and 12 months) (low elevation station precipitation anomaly maps for the last 1, 3, 12 months) (climate engine model percent of normal precipitation map for the last month: PR and USVI, Caribbean and Gulf of Mexico region).

Root zone analysis indicated that soil conditions were dry across the western and southern coasts of PR (root zone soil saturation fraction, SPoRT estimates of soil moisture at four depths [0-10 cm, 10-40 cm, 40-100 cm, 100-200 cm]). Satellite observations of vegetative health (stressed vegetation for PR and USVI, drought stress for PR and USVI, VHI for PR and USVI) revealed areas of stressed vegetation in eastern PR. Monthly streamflow on PR showed mostly near- to above-normal stream levels. In the USVI, groundwater levels rose early in February then declined at St. John, St. Thomas, and St. Croix, but ended the month rising again at St. Croix and St. Thomas. The end-of-February groundwater level continued well in the bottom third of the recent historical record at St. Croix, but was in the upper third at St. John.

In the USVI, abnormal dryness and drought ended on St. Croix and St. John, while severe drought improved to moderate drought on St. Thomas. On PR, moderate drought contracted to cover about 40.7% of the territory on the February 27, 2024 USDM map, compared to 53.9% at the end of January.

CONUS State Precipitation Ranks

February 2024 was drier than normal across most of the Northeast, Midwest, and Mid-Atlantic, and parts of the Gulf Coast, northern Plains, and Pacific Northwest, with record dryness locally in parts of the Mid-Mississippi Valley and Northeast. Twenty-five states had a precipitation rank in the driest third of the 130-year historical record for February, including 12 that ranked in the top ten driest category — Illinois, New York, Vermont, New Hampshire, and Maine, each of which ranked second driest; Iowa and Massachusetts, both third driest; Connecticut and Rhode Island, both seventh driest; Michigan (eighth driest); Missouri (ninth driest); and North Carolina (tenth driest) — and one that was close: New Jersey (12th driest).

The year to date (January-February 2024) was drier than normal across the northern Plains, Upper Midwest, most of the Rio Grande Valley, and parts of New England and the Southeast Coast. Five states had a precipitation rank in the driest third of the 1895-2024 record for January-February, including one that ranked in the top ten driest category — North Dakota (tenth driest).

The winter (December 2023-February 2024) was drier than normal in parts of the northern Plains, Upper Midwest, Rio Grande Valley, northern Rockies, Southwest, and Deep South. Three states had a precipitation rank in the driest third of the historical record for December-February, but near- to above-normal precipitation fell in other parts of states that were unusually dry, so no state ranked in the top ten driest category.

The last six months (September 2023-February 2024) were drier than normal across the Mississippi, Ohio, and Tennessee valleys, most of the Southwest and Rio Grande Valley, and a few parts of the Pacific Northwest, Plains, and Mid-Atlantic coast. Thirteen states had a precipitation rank in the driest third of the historical record for September-February. None ranked in the top ten driest category, but one was close — Tennessee (13th driest).

The last 12 months (March 2023-February 2024) were drier than normal across the Mississippi, Ohio, Tennessee, and Rio Grande valleys, most of the Southwest (Four Corners States), and parts of the Pacific Northwest, Plains, and Mid-Atlantic coast. Fourteen states had a precipitation rank in the driest third of the historical record for March-February, including one that ranked in the top ten driest category — Iowa (ninth driest).

Agricultural Belts

During February 2024, the Primary Hard Red Winter Wheat agricultural belt was warmer than normal and wetter than normal in the north but drier than normal in the south. The month ranked as the 47th wettest and third warmest February, regionwide, in the 1895-2024 record.

October marks the beginning of the growing season for the Primary Hard Red Winter Wheat belt. October 2023-February 2024 was mostly warmer and wetter than normal. The period ranked as the 28th wettest and fifth warmest October-February, regionwide, on record.

According to the U.S. Department of Agriculture (USDA), as of February 27, 2024, drought affected approximately 24% of barley production, 30% of corn production, 11% of cotton production, 13% of sorghum production, 28% of soybean production, 29% of spring wheat production, 14% of winter wheat production, 17% of hay acreage, 16% of the cattle inventory, 17% of the milk cow inventory, and 18% of the sheep inventory.

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 [ROP], American Samoa, basinwide), February 2024 was drier than normal in the Marianas, Marshalls, and western to central FSM, but near to wetter than normal in Palau, American Samoa, and the southern and eastern 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) in the Marianas, Marshalls, and most of the FSM. February precipitation was above the monthly minimums in Palau and American Samoa, and at Pohnpei, Kosrae, and Kapingamarangi (in the FSM). 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 February 2024, which was in the wet season for American Samoa, and in the dry season for the Micronesia region. Precipitation was below the monthly minimum but above normal (1981-2010 normal), because the normals are low, at:

  • Ailinglaplap: February 2024 precipitation 6.13 inches, February normal mean 4.92 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 Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec
2023
Jan
2024
Feb
2024
Mar-
Feb
Chuuk85%137%191%118%130%118%112%110%141%100%100%76%115%
Guam NAS263%198%916%146%86%132%98%152%84%107%59%62%126%
Kapingamarangi116%141%137%145%162%121%256%117%153%74%188%206%133%
Koror185%77%165%77%145%125%130%108%85%67%136%140%109%
Kosrae67%120%87%166%132%104%123%153%163%44%90%119%94%
Kwajalein189%188%345%143%45%81%61%103%156%111%53%52%117%
Lukonor96%77%61%116%75%74%115%136%81%94%64%76%78%
Majuro169%151%102%105%70%95%56%86%101%70%57%74%91%
Pago Pago106%152%168%109%102%42%156%91%36%195%142%201%116%
Pohnpei109%141%145%121%148%219%156%83%178%48%50%170%126%
Saipan138%192%225%92%46%142%109%92%133%158%74%79%110%
Yap137%104%131%121%168%145%70%88%79%41%90%55%102%
Pacific Island Precipitation (Inches)
Station Name Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec
2023
Jan
2024
Feb
2024
Mar-
Feb
Chuuk7.09"17.14"21.57"13.73"15.56"15.23"13.07"12.70"14.93"11.22"10.05"5.49"157.78"
Guam NAS5.45"5.01"31.15"9.00"8.69"19.47"12.46"17.40"6.18"5.49"2.38"1.88"124.56"
Kapingamarangi13.24"19.19"16.59"20.04"22.86"9.87"25.45"9.55"14.14"7.33"17.18"19.05"194.49"
Koror13.74"5.60"19.53"13.44"26.81"16.86"15.26"12.80"9.65"7.46"13.85"11.97"166.97"
Kosrae10.81"21.08"15.41"24.30"19.67"14.72"17.52"16.79"22.60"7.06"15.04"15.43"200.43"
Kwajalein4.43"9.87"23.18"9.93"4.45"7.86"6.60"11.46"17.65"7.42"1.66"1.37"105.88"
Lukonor8.92"8.68"7.13"13.55"11.89"10.33"11.63"15.43"7.40"10.54"5.42"6.83"117.75"
Majuro11.12"14.23"10.35"11.56"7.87"11.07"6.27"10.98"13.51"7.96"4.38"5.11"114.41"
Pago Pago11.34"14.25"16.19"5.81"5.64"2.26"10.18"8.45"3.69"25.00"18.99"24.09"145.89"
Pohnpei14.29"25.90"29.02"17.94"22.76"31.21"19.57"12.71"26.39"7.76"6.65"16.27"230.47"
Saipan2.61"5.05"5.35"3.34"4.13"18.62"11.03"9.80"7.44"6.07"1.87"2.05"77.36"
Yap6.26"5.86"10.28"14.59"25.35"21.43"9.46"10.74"6.95"3.53"5.73"2.84"123.02"
Pacific Island 1981-2010 Normal Median Precipitation (Inches)
Station Name Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec
2023
Jan
2024
Feb
2024
Mar-
Feb
Chuuk8.32"12.47"11.30"11.66"11.98"12.86"11.71"11.51"10.61"11.25"10.10"7.25"136.77"
Guam NAS2.07"2.53"3.40"6.18"10.14"14.74"12.66"11.44"7.38"5.11"4.01"3.03"99.09"
Kapingamarangi11.43"13.64"12.08"13.78"14.15"8.13"9.93"8.19"9.27"9.84"9.15"9.27"145.85"
Koror7.44"7.32"11.83"17.48"18.53"13.50"11.77"11.84"11.39"11.16"10.18"8.56"152.90"
Kosrae16.06"17.51"17.75"14.64"14.91"14.22"14.22"10.94"13.83"16.11"16.67"12.93"213.87"
Kwajalein2.35"5.26"6.72"6.93"9.87"9.74"10.74"11.18"11.28"6.66"3.16"2.64"90.41"
Lukonor9.26"11.31"11.69"11.65"15.93"14.04"10.15"11.32"9.08"11.27"8.41"8.93"151.36"
Majuro6.58"9.42"10.11"11.01"11.17"11.69"11.17"12.73"13.44"11.39"7.74"6.88"125.25"
Pago Pago10.68"9.39"9.66"5.33"5.55"5.38"6.53"9.26"10.14"12.84"13.34"12.00"125.57"
Pohnpei13.17"18.41"19.96"14.81"15.43"14.26"12.55"15.27"14.83"16.08"13.18"9.55"182.36"
Saipan1.89"2.63"2.38"3.62"8.91"13.13"10.09"10.62"5.61"3.85"2.53"2.59"70.25"
Yap4.56"5.63"7.85"12.04"15.08"14.82"13.50"12.18"8.83"8.51"6.39"5.19"120.31"

As measured by percent of normal precipitation, Lukunor and Majuro were drier than normal at all time scales in the short term (February, the year-to-date [January-February], and the last 3 months [December-February]) and long term (last 12 months [March 2023-February 2024]). Chuuk, Guam, Kwajalein, Saipan, and Yap were drier than normal in the short-term and wetter than normal in the long-term. Kosrae was wetter than normal for February but drier than normal for the other short-term time scales and drier than normal in the long-term. Pohnpei was drier than normal for the last 2 and 3 months but wetter than normal for February and in the long-term. Airai was near to drier than normal for December-February but wetter than normal for the other 3 time scales. Kapingamarangi and Pago Pago were wetter than normal at all 4 time scales.

Based on percent of normal average (instead of normal median values), in the Marianas Islands, February and the last 3 months were mostly drier than normal across the main islands. Wetter-than-normal conditions dominated at the 12-month time scales (percent of normal precipitation maps for the last 1, 3, 12 months).

Based on percent of normal average (instead of normal median values), the Marshall Islands were mostly drier than normal for February and the last 3 months, with a mixed anomaly pattern dominating at 12 months (percent of normal precipitation maps for the last 1, 3, 12 months).

According to the February 29 USDM produced for the USAPI, abnormal dryness in the Marianas worsened to moderate drought at Guam and Rota and to severe drought at Saipan; in the Marshalls, moderate drought worsened to severe drought at Kwajalein and Wotje but improved to abnormal dryness at Majuro, while abnormal dryness continued at Jaluit; in the FSM, severe drought continued at Ulithi and Yap, moderate drought worsened to severe drought at Pingelap, abnormal dryness developed at Chuuk and Nukuoro and worsened to moderate drought at Woleai, moderate drought improved to abnormal dryness at Pohnpei, and abnormal dryness continued at Lukunor. The rest of the USAPI stations were free of drought and abnormal dryness. The level of the reservoir on Majuro rose early in the month to a peak of 29.3 million gallons on February 6 but steadily declined thereafter to a minimum of 25.4 million gallons; rain on the 21st bumped the reservoir level up a bit, but it declined since then to end the month at 24.5 million gallons. If the reservoir dips below 28.8 million gallons, drought becomes a concern. Satellite observations of vegetative health (drought stress, stressed vegetation, VHI) indicated few areas of stressed vegetation on Guam.

The National Weather Service (NWS) office in Guam issued two Drought Information Statements (DGT) for drought for February (on February 16 and March 1). Drought impacts included low water catchment levels on some islands, with water shortages occurring for communities on the outer islands of Pohnpei State, Yap State, and the northern RMI. Wildfires have been reported on Guam.

February 2024 precipitation ranks ranged from very dry to very wet, with some mid-range between wet and dry, based on data available at the time of this report. Short-term dryness was balanced by long-term wetness at some locations:

  • Nukuoro: fourth driest February (in a 42-year record).
  • Pingelap: sixth driest February (42 years), second driest November-February, August-February, and July-February, and fifth driest March-February (last 12 months).
  • Guam: 16th driest February (67 years) and sixth driest November-February, but fifth wettest March-February (last 12 months).
  • Lukunor: 12th driest February (40 years), sixth driest November-February, fifth driest May-February, and sixth driest March-February (last 12 months).
  • Ulithi: 21st driest February (41 years), but eighth driest November-February and ninth driest September-February.
  • Woleai: 15th driest February (40 years), but ninth driest December-February.
  • Yap: 18th driest February (73 years), but eighth driest November-February and fifth driest September-February.
  • Jaluit: 17th driest February (41 years), but ninth driest December-February, eighth driest September-February and August-February, fifth driest July-February back through April-February, and fourth driest March-February (last 12 months).
  • Wotje: 12th driest February (41 years), but sixth driest July-February.
  • Kwajalein: 23rd driest February (72 years), but seventh driest July-February.
  • Majuro: 29th driest February (70 years), but ninth driest September-February and fifth driest July-February, June-February, and May-February.

At the wet end of the scale:

  • Kapingamarangi had the fifth wettest February (37 years) and wettest July-February back through April-February.
  • Pohnpei had the 14th wettest February (73 years) and wettest May-February and April-February.

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 November 2023, June-November 2023 (last 6 months), and December 2022-November 2023 (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.

February 2024 USAPI Precipitation Ranks (1 = driest)
StationFebruary 2024Sep 2023-Feb 2024Mar 2023-Feb 2024Period of Record
RankYearsRankYearsRankYears
Ailinglaplap2841263934381981-2024
Airai5473367355711951-2024
Chuuk2873347358721951-2024
Fananu--8--5--22003-2023
Guam1667226763671957-2024
Jaluit17418394381981-2024
Kapingamarangi3337232418191962-2024
Kosrae3358224017351954-2024
Kwajalein2372247246711952-2024
Lukunor124013386271981-2024
Majuro297097017691954-2024
Mili--39--35--341981-2024
Nukuoro442184024391981-2024
Pago Pago5358495845571966-2024
Pingelap6424385361981-2024
Pohnpei6073427370721951-2024
Saipan1744183627351981-2024
Ulithi214193828361981-2024
Utirik--19--9--31985-2020
Woleai15401535--271968-2024
Wotje1241103822371981-2024
Yap187357337721951-2024
Map of USAPIFebruary 2024 Precipitation (Inches)
Map of USAPI February 2024 Percent of Normal Precipitation
Map of USAPI January-February 2024 Percent of Normal Precipitation
Map of USAPI December-February 2024 Percent of Normal Precipitation
Map of USAPI March 2023-February 2024 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, temperatures were above average across much of the Southeast in February, except the Florida Peninsula where temperatures were below average, and precipitation was variable across the region. The driest locations were found across the northern Gulf Coast, northern portions of Alabama, Georgia, and South Carolina, and all of North Carolina, where monthly totals were 1 to 3 inches (25 to 76 mm) below average (less than 50 percent of normal). Bay Minette, AL, located along the Gulf Coast, recorded just 0.86 inch (22 mm) of precipitation, making it the driest February on record (since 1913). Lincolnton, NC recorded 0.94 inch (24 mm), which ranked as the fourth driest February on record (since 1953). Charlotte, NC also recorded 0.94 inch (24 mm), while Pensacola, FL recorded 1.37 inches (35 mm), both less than one-third of their expected monthly totals.

Drought conditions improved in some parts of the Southeast and worsened in other areas, yielding little overall change throughout the month. Moderate (D1) drought was eliminated across northern portions of Alabama and Georgia, as well as along the West Coast of Florida, with small areas of abnormal dryness (D0) remaining at the end of the month. On the other hand, moderate (D1) drought emerged across northeastern North Carolina, while abnormal dryness (D0) expanded across eastern portions of the Carolinas and coastal Alabama. By the end of the month, more than 85 percent of the region was free of any drought designation. There was also relatively little change in drought conditions across Puerto Rico. Moderate (D1) drought persisted across the northwest, southwest, and eastern portions of the island, with abnormal dryness (D0) found elsewhere, except across the northeast and southeast coasts (including San Juan). In contrast, drought conditions improved in the U.S. Virgin Islands. Saint Thomas improved from severe (D2) to moderate (D1) drought, while Saint John and Saint Croix were free of any drought designation at the end of the month. Generally above-average temperatures and dry weather across large portions of the region allowed farmers to prepare fields for spring planting.

South

As explained by the Southern Regional Climate Center, temperatures were above normal across the Southern region during February, with the greatest departures in the northern areas of the region, and monthly precipitation was generally below normal in the region with isolated areas of well above-normal precipitation. The largest well-documented wildfire in Texas state history began on February 26th, impacting large areas of the Texas Panhandle and western Oklahoma.

During February the Southern region saw a mix of improvement and degradation in drought conditions. Widespread improvements took place across much of Louisiana, Mississippi, and Tennessee, with some areas seeing up to three categories of improvement in drought conditions according to the USDM. One to two classes of degradation were assigned to portions of West Texas, eastern Oklahoma, western Arkansas, coastal Mississippi, and Tennessee. Drought conditions in Far West Texas remained largely unchanged. There are currently no Exceptional Drought Conditions in the Southern region as of March 5th. Oklahoma and Arkansas remain largely drought-free, but Abnormally Dry conditions are emerging according to the USDM. With widespread precipitation across the region in January, soil moisture values have generally rebounded across the region. According to modeled soil moisture values from the Climate Prediction Center, much of the region is averaging between the 30th and 70th historical percentile value for February, with areas of Far West Texas, Louisiana, and Mississippi showing modeled values in the 10th through 30th percentile for February. Despite widespread improvements in drought conditions, flows on the Mississippi River south of St. Louis are still well below their historical mean values for this time of year. Impacts from ongoing drought in Mississippi include up to 12.5 million estimated dead trees due to drought and Pine Beetle infestations, limiting uses for salvage timber, and up to a fifty percent reduction in the annual duck migration through the area, partially due to no flood irrigation of fields from the ongoing drought.

Midwest

As described by the Midwest Regional Climate Center, the average February temperature for the Midwest was 36.1 degrees F (2.3 degrees C), which was 9.8 degrees F (5.4 degrees C) above the 1991-2020 normal. Based on preliminary rankings, February was the warmest on record, dating back to 1895. February precipitation totaled 0.91 inch (23 mm) for the Midwest, which was 0.93 inch (24 mm) below normal, or 49 percent of normal. Precipitation deficits of 1.5 to 3.5 inches (38.1 to 88.9 mm) were widespread across the central and lower Midwest, with deficits of 0.5 to 1.5 inches (12.7 to 38.1 mm) across Iowa, Wisconsin, and Michigan. Only eastern Kentucky and northern Minnesota had above-normal precipitation. Preliminary statewide precipitation totals ranged from 0.2 inch (5 mm) below normal in Minnesota to 1.62 inches (41 mm) below normal in Missouri. Preliminary rankings indicate Iowa had its 3rd driest February while Illinois had its 4th driest. The Midwest region tied for the 10th driest February. Preliminary total winter (December-February) precipitation was 5.95 inches (151.1 mm), which was 0.2 inch (5.1 mm) below normal for the season. The entire Midwest, except a small area of southern Illinois, had below-normal snowfall, with deficits of 5 to 25 inches (12.7 to 63.5 cm) across the upper Midwest. The region also had a remarkable lack of snow cover throughout the month as warm temperatures rapidly melted any snow soon after it fell. Much of the region saw bare ground for the majority of February.

Dry conditions expanded during February, ending the month with about 73 percent of the region abnormally dry or in drought compared with 54 percent of the region to start the month. Only Kentucky ended the month free of any drought or dryness. The epicenter of drought severity remained parked over Iowa, where 79 percent of the state was affected by moderate (D1) to extreme (D3) drought on the USDM map. Abnormal dryness spread across Missouri, Illinois, and Michigan, while moderate (D1) drought expanded across the upper Midwest. Dry conditions resulted in several brushfires and hotspots in Missouri, Illinois, and Iowa.

Northeast

As summarized by the Northeast Regional Climate Center, a warm, dry February closed out a record-warm, record-wet winter that featured below-normal snowfall. The Northeast had its fifth warmest February since records began in 1895 with an average temperature of 31.6 degrees F, 5.2 degrees F above normal, and sixth driest February, seeing 1.19 inches of precipitation, 43 percent of normal. The USDM from February 6 showed less than one percent of the Northeast in severe drought, less than one percent in moderate drought, and three percent as abnormally dry. Recovering groundwater levels led to improvements in southeastern Massachusetts, with severe drought easing on Nantucket, moderate drought improving on Martha's Vineyard, and abnormal dryness erased from Cape Cod. Additionally, enough precipitation fell in southwestern West Virginia to ease abnormal dryness there. However, with limited precipitation during February, pockets of moderate drought and/or abnormal dryness persisted in western New York and northwestern Pennsylvania. The USDM from February 27 showed less than one percent of the Northeast in moderate drought and three percent as abnormally dry. At times during February, a few locations including western New York, western Pennsylvania, and parts of West Virginia saw below-normal or much below-normal 7-day streamflow, based on USGS streamgages. Additionally, below-normal or lower groundwater levels were reported during the month in places like western and central New York, western Pennsylvania, and Nantucket, Massachusetts.

High Plains

As discussed by the High Plains Regional Climate Center, February capped off a very typical El Niño pattern for the High Plains, with warmer temperatures and below-normal precipitation across the northern portions of the region. These conditions this winter took a toll, with the impacts rearing their head in late February. Snow was hard to come by, with the historic snow drought continuing through this month. Snowpack is at or near record lows, with measures being taken to account for the low runoff this year. On the flipside, the low snowpack has reduced the chances of flooding this spring drastically. Outside of a cold snap in the middle of January, unseasonably warm temperatures have dominated (record to near-record warmth). Plants began blooming weeks earlier than usual across Kansas and parts of Colorado and Nebraska. The dryness and warmer temperatures also led to a rash of wildfires late in the month, with the largest taking place outside North Platte, Nebraska. Wind gusts over 40 mph (64 km/h) rapidly spread the fire, with over 71,000 acres (111 square miles) consumed by the fire. Minimal property damage occurred due to the sparse population of Lincoln County. However, a state disaster declaration was issued.

The eastern parts of the High Plains were nearly bone-dry, with no form of precipitation whatsoever. Lincoln, Nebraska, and Mobridge, South Dakota recorded trace amounts of snowfall in February, tying their lowest snowfall for the month. The areas around Omaha, Nebraska, and Sioux Falls, South Dakota received less than 0.10 inch (2.54 mm) of precipitation this month, leading to concerns heading into spring. On the opposite end of the spectrum, the snow drought was prevalent across the Dakotas. Warmer temperatures limited snowfall this winter, with many locations ranking in the top 10 lowest. While snowfall amounts were low, that did not necessarily mean low precipitation. Fargo, North Dakota recorded their second wettest winter with 3.83 inches (9.73 cm) of precipitation, while Sisseton, South Dakota ranked 4th wettest with 3.92 inches (9.96 cm).

While overall drought conditions did not improve much this month, the intensity was reduced in the region. Precipitation did occur, albeit not desperately needed snow in the northern High Plains. Overall, the region experienced a minor reduction of less than 1 percent of D0 to D4 (abnormally dry to exceptional drought conditions). Drought began to reemerge across the Dakotas and northern Wyoming due to the snow drought. Parts of North Dakota did receive record precipitation this winter, however, this was predominantly rain or sleet. The lack of snowfall and warm temperatures have led to growing concerns that insect populations will be above normal this year in the state. On a more optimistic note, the region is now free of extreme drought (D3) for the first time since May 2020. The last remnants were erased in Colorado and Kansas this month, providing a sense of relief and optimism heading into spring. Elsewhere in the region, other improvements and degradation were observed.

West

As summarized by the Western Regional Climate Center, February brought above-normal temperatures and above-normal precipitation to most of the West. A stronger-than-normal subtropical jet stream helped drive several strong atmospheric rivers into the coast of southern California and through the Southwest, bringing heavy rainfall and flooding in some cases. Despite above-normal precipitation in western Montana, snowpack was at record-low levels for some locations at the end of February leading to expansion of severe and extreme drought in the region. According to the USDM at the end of February, 27 percent of the West was in drought. Areas of extreme (D3) and exceptional (D4) drought are found in far southeast Arizona, New Mexico, and western Montana. Despite the remaining drought in Arizona and New Mexico, much of the region saw one and two category improvements in February. In western Washington and southeast Montana one and two category drought degradations occurred.

Alaska summary: Temperatures were above normal across most of Alaska with the warmest areas being the western and northern part of the state. Precipitation was below normal for the Panhandle, Interior, and much of Southcentral and above normal for much of southwest Alaska. In the southern Panhandle, Petersburgh had its seventh driest February with 2.76 inches of precipitation at 36 percent of normal and Ketchikan also had its seventh driest February with 4.25 inches of precipitation at 36 percent of normal. On the wet side of things, Bethel saw its fourth wettest February, King Salmon the sixth wettest, and Utqiagvik the seventh wettest.

Hawaii summary: It was a dry month across Hawaii with most of the long-term climate stations reporting well below-normal February precipitation. Lihue received 0.92 inch of precipitation, 25 percent of normal, making it the 12th driest on record; Honolulu logged 0.30 inch, 15 percent of normal, for the sixth driest on record; and Molokai recorded 1.49 inches at 66 percent of normal. According to the USDM at the end of February, 66 percent of Hawaii was abnormally dry (D0) with ten percent in moderate drought (D1). During February, D0 was added to all of Kauai, Oahu, and much of Maui.

Additional Resources

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Citing This Report

NOAA National Centers for Environmental Information, Monthly Drought Report for February 2024, published online March 2024, retrieved on July 20, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/drought/202402.