NOAA's National Centers for Environmental Information
Issued 12 July 2024
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 4% of the contiguous United States as of the end of June 2024, a decrease of about 1% from last month. About 4% of the contiguous U.S. fell in the severely to extremely wet categories.
- About 11% of the contiguous U.S. fell in the moderate to extreme drought categories (based on the Palmer Drought Index) at the end of June.
- 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 July 2, 2024, 18.67% of the contiguous U.S. (CONUS) (15.81% of the U.S. including Alaska, Hawaii, and Puerto Rico) was classified as experiencing moderate to exceptional (D1-D4) drought.
Detailed Drought Overview
The upper-level atmospheric circulation over North America during June 2024 was dominated by a ridge of high pressure across the southern CONUS that brought unusually warm temperatures to much of the country, especially the Southwest. The ridge forced the jet stream north to the U.S.-Canadian border. Another ridge across western Canada and Alaska funneled short-wave troughs and closed lows across the northern U.S. and southern Canada in this rather flat (or zonal) jet stream flow. Surface low-pressure systems and fronts associated with these upper-level features tracked mostly along the U.S.-Canadian border. Some of the fronts penetrated the ridge to reach the southern states. Fed by Pacific and Gulf of Mexico moisture, these systems spread above-normal precipitation across the Upper Midwest, parts of the northern and central Plains and New England, and much of the Southwest. Southern Florida was drenched by tropical moisture and Tropical Storm Alberto spread rain across southern Texas as it tracked into Mexico. The precipitation in the Four Corners States was enhanced by the Southwest summer monsoon and possibly moisture from the remnants of Alberto. Much of the Southeast, Ohio Valley, and Mid-Atlantic region was starved of moisture, so June ended up drier than normal with some record-dry conditions. The upper-level systems sometimes distorted the ridge/trough pattern throughout the month, with ridging bringing excessively hot temperatures to the Northeast at times and to the West at other times. Outside of the Four Corners States and parts of the Pacific Northwest Coast, the western ridge inhibited precipitation across most of the West. Ridging gave Alaska a mostly warmer- and drier-than-normal month and kept temperatures warmer than normal across Puerto Rico and the U.S. Virgin Islands. A dry trade-wind pattern gave much of Hawaii a drier-than-normal June.
The above-normal precipitation in the Southwest, Upper Midwest, the southern half of the Florida peninsula, parts of the Plains, and a few parts of the Pacific Northwest contracted or reduced the intensity of drought and abnormal dryness compared to the end of May. But dry conditions in parts of the southern Plains and Pacific Northwest to western High Plains resulted in expansion or intensification of drought and abnormal dryness, and flash drought conditions in the Southeast, Ohio Valley, and Mid-Atlantic region prompted rapid expansion of drought and abnormal dryness there. Drought and abnormal dryness also expanded in parts of Alaska and Hawaii. Drought expansion exceeded contraction with the USDM-based national moderate-to-exceptional drought footprint across the CONUS increasing from 12.6% at the end of May to 18.7% at the end of June (from 10.5% to 15.8% for the 50 states and Puerto Rico).
According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 10.7% of the CONUS was in moderate to extreme drought at the end of June, which is less than the end of May.
Drought conditions at the end of June, as depicted on the July 2, 2024 USDM map, included the following core drought and abnormally dry areas:
- In the West, moderate (D1) to severe (D2) drought covers about 23.5% of the Pacific Northwest, which is more than last month, and moderate to exceptional (D4) drought affected about 22.3% of the Southwest (Four Corners states), which is less than last month. For the West as a whole, the percent area experiencing moderate to exceptional drought, according to USDM statistics, stayed about the same, changing from 18.9% at the end of May to 18.8% at the end of June. Based on the Palmer Drought Index, the drought area across the West as a whole decreased from 16.5% at the end of May to 8.6% at the end of June. Reservoir levels were near to above average in most basins, with low reservoir levels in some basins in the Southwest and Pacific Northwest.
- New Mexico set a new drought duration record at the end of June. According to USDM statistics, New Mexico has experienced moderate or worse drought for 350 weeks, beginning on October 24, 2017.
- In the Great Plains, moderate to severe drought covered about 12.1% of the central to northern Plains, which is less than last month, and 30.7% of the southern Plains, which is also less than last month. The Lower Mississippi River Valley experienced a slight increase in the drought area , going from 0.5% at the end of May to 3.3% at the end of June. Drought returned to Tennessee this month, covering 25.8% of the state by the end of June. Taken together, the southern Plains, Lower Mississippi Valley, and Tennessee (South region) saw moderate to extreme drought expand from 15.8% at the end of May to 19.7% at the end of June.
- Oklahoma set a new drought duration record at the end of June. According to USDM statistics, Oklahoma has experienced moderate or worse drought for 258 weeks, beginning on July 30, 2019.
- Drought contracted in northern parts of the Midwest but returned to southern parts. Moderate drought expanded from 0.8% at the end of May to 5.6% at the end of June. Moderate drought ended in Missouri in early June, terminating a USDM drought duration record of 102 weeks, beginning on June 28, 2022 and ending on June 4, 2024. But moderate drought quickly returned, covering 4.4% of the state by July 2.
- Drought massively expanded in the Southeast this month, growing from 6.7% at the end of May to 53.3% at the end of June. Moderate to severe drought ended in the southern part of the Florida peninsula but rapidly developed in states to the north.
- Drought returned to the Northeast this month, covering 12.2% of the region by the end of June. Moderate to severe drought was mostly in southern parts of the region.
- Moderate to severe drought expanded slightly in Hawaii, covering 8.9% of the state by the end of June.
- In the U.S.-Affiliated Pacific Islands (USAPI), 3 stations were abnormally dry, 1 was experiencing moderate drought, and 2 were experiencing severe drought conditions. This compares to 2 abnormally dry, 2 with moderate drought, 1 with severe drought, and 4 with extreme drought at the end of May.
Palmer Drought Index
The Palmer drought indices measure the balance between moisture demand (evapotranspiration driven by temperature) and moisture supply (precipitation). The Palmer Z Index depicts moisture conditions for the current month, while the Palmer Hydrological Drought Index (PHDI) and Palmer Drought Severity Index (PDSI) depict the current month's cumulative moisture conditions integrated over the last several months.
While both the PDSI and PHDI indices show long-term moisture conditions, the PDSI depicts meteorological drought while the PHDI depicts hydrological drought. The PDSI map may show less severe and extensive drought (as well as wet spell conditions) in some parts of the country than the PHDI map because the meteorological conditions that produce drought and wet spell conditions are not as long-lasting as the hydrological impacts.
Used together, the Palmer Z Index and PHDI maps show that short-term drought occurred in parts of the northern Rockies, shrinking long-term wet conditions, in parts of the southern Plains, reinforcing long-term drought, and in parts of the central Plains and much of the Ohio Valley, Southeast, and Mid-Atlantic, intensifying or introducing long-term drought (PHDI maps for June compared to May). Short-term wet conditions occurred in the Upper Midwest and eastern parts of the northern Plains, expanding and intensifying long-term wet conditions, and in the Southwest and in southern Florida, shrinking or eliminating 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.
The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Severely dry conditions covered a massive area from northern Florida to Pennsylvania and westward to the Mid-Mississippi Valley at the 1-month time scale. This dryness was so severe that it was evident in places at the 2- and 3-month maps. Dry conditions persisted in parts of eastern North Carolina at all time scales, and in parts of the Mid-Mississippi to Mid-Atlantic region at 9 to 24 months. Large parts of the West were dry at 1 to 3 months, with parts of the Pacific Northwest and northern Rockies dry at 6 months, and large parts of the Pacific Northwest dry at 9 to 24 months. Parts of the Rio Grande River Valley are dry at all time scales. Dryness shows up in parts of the Lower Mississippi Valley at 9- to 12-month time scales. Parts of Oklahoma have dry conditions at 1 to 6 months, while parts of the central Plains are dry at 12 months and much of the central Plains to Ohio River Valley have dry conditions at 24 months. Wet conditions dominate much of the Upper Midwest at all time scales, the Southwest at 1 to 6 months, parts to much of the West at 6 to 24 months, much of the Gulf of Mexico Coast to Tennessee Valley at 2 to 6 months, most of the Northeast at 6 to 24 months, and east Texas at 2 to 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.
For the Northern Hemisphere, June marks the beginning of climatological summer, which is the season when sun angle, temperatures, and evapotranspiration are maximum. During June 2024, temperatures were warmer than normal across much of the CONUS, especially in the West, South, and East, with record warmth in parts of the Southwest. Evapotranspiration was unusually high, especially in those areas that were excessively hot and unusually dry. The 1-month SPEI values were more extreme (dry) than the corresponding SPI in the Far West, where it was hot and dry. In the Ohio Valley, Mid-Atlantic, and Southeast, the June SPI and SPEI were comparable due to the extremely dry conditions. Even though temperatures were unusually warm across much of the CONUS for the last 3 to 6 months, precipitation was fairly evenly distributed or wet (except in a few areas) during this period, so the SPEI and SPI maps had similar magnitudes for most areas for much of this period (SPEI maps for the last 1, 2, 3, 6, 9, 12 months) (SPI maps for the last 1, 2, 3, 6, 9, 12 months).
The combination of heat and dryness in the Mid-Atlantic region resulted in record low SPEI and near-record low SPI values:
- North Carolina had a record dry 1-month June SPEI while the SPI was second lowest on record. The state also ranked second driest on record for precipitation and 16th warmest for temperature.
- Virginia had a record dry 1-month June SPEI while the SPI was second lowest on record. The state also ranked driest on record for precipitation and eighth warmest for temperature.
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). Precipitation in the last 12 months has helped reduce deficits in many areas. But June 2024 was very dry from the Ohio Valley to Mid-Atlantic and Southeast, and the last 2 years have been extremely dry in the Pacific Northwest, the last 3 years were dry along the North Carolina coast, the last 2 to 3 years have been very dry from the central Plains to Mid-Mississippi Valley and in the Rio Grande Valley, and the last 4 to 5 years have been quite dry in the West to Great Plains (state precipitation rank maps for the last 1, 2, 3, 4, 5 years) (climate division precipitation rank maps for the last 1, 2, 3, 4, 5 years). In the last 1 to 6 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, especially at the longer time scales (SPEI maps for last 12, 24, 36, 48, 60, 72 months) (SPI maps for last 12, 24, 36, 48, 60, 72 months).
The 24-month SPEI for New Mexico is more extreme than the corresponding SPI, ranking third driest on record compared to the SPI which is barely in the top 20 driest category. The 12- to 48-month SPEI for a couple climate divisions in Louisiana and Texas is record dry where the corresponding SPI is not record dry (or barely in the top ten):
- Southeast Louisiana (climate division 9) (24-month SPEI, SPI)
- Texas Trans Pecos (climate division 5) (12-month SPEI, SPI)
- Texas Trans Pecos (climate division 5) (24-month SPEI, SPI)
- Texas Trans Pecos (climate division 5) (48-month SPEI, SPI)
Regional Discussion
Rio Grande River Basin
During October 2023-June 2024, parts of the Rio Grande River Basin were 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. June 2024 was near to wetter than normal, except in the Trans Pecos region, but the previous two months (April and May 2024) were mostly drier than normal. The basin had the 36th wettest June in the 1895-2024 record, but 23rd driest July-June (last 12 months). Temperatures have also been anomalously warm — June ranked hottest in the 130-year record, as did July-June (last 12 months). According to the USDM, 67.0% of the basin was in moderate to exceptional drought at the end of June, which is less than the 75.4% at the end of May. Based on the Palmer Drought Index, 66.7% of the basin was in moderate to extreme drought at the end of June, which is less than the end of May 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
June 2024 was drier than normal across most of the main Hawaiian Islands, except for some stations on the lee side of the Big Island. Wet conditions in May resulted in wetter-than-normal conditions for the last 2 to 3 months. But some areas were drier than normal at the 4- to 6-month time scales, especially across Molokai, Maui, Lanai, and the lee slopes (western half) of the Big Island. A mixed precipitation anomaly pattern was evident at the 12-month time scale, except across the Big Island where it was mostly drier than normal (precipitation anomaly maps for the last 1, 2, 3, 4, 6, 12 months) (climate engine model percent of normal precipitation map for the last month).
Monthly streamflow was mostly near to above normal across the main islands. Based on satellite analyses (stressed vegetation, drought stress, VHI), vegetation was stressed on parts of the Big Island, Molokai, and Maui.
Moderate to severe drought continued on the Big Island and Maui. The drought area in Hawaii increased slightly from 8.2% at the end of May to about 8.9% of the state on the July 2, 2024 USDM map.
Alaska
Alaska was drier than normal during June. Drier-than-normal conditions dominated for the last 2 to 3 months. A mixed precipitation anomaly pattern was evident at the 6-month time scale, with dry conditions most prevalent from Cook Inlet to the Northeast Interior and in the South Panhandle. Wetter-than-normal conditions dominated at 12 months, except in the Aleutians (low elevation station precipitation anomaly maps for the last 1, 2, 3, 4, 6, 12 months) (high elevation SNOTEL station precipitation percentile maps for the last 1 and 3 months) (SNOTEL basin and station percent of normal precipitation maps for the last 1 and 3 months) (climate division precipitation rank maps for the last 1, 3, 6, and 12 months) (climate engine model percent of normal precipitation map for the last month) (Leaky Bucket model precipitation percentile map) (ACCAP percent of average precipitation map).
June temperatures were predominantly warmer than average (long-term average) across the state, with some cooler-than-normal stations (1991-2020 normals) in the north and along the Aleutians. Some stations were cooler than normal at the 2- and 3-month time scales, but most areas were warmer than average. Warmer-than-average temperatures dominated across the state at 4 to 12 months, with some cooler-than-normal stations. The difference between the long-term average and 30-year normals is due to a pronounced warming trend in recent decades (low elevation station temperature anomaly maps for the last 1, 2, 3, 4, 9, 12 months) (climate division temperature rank maps for the last 1, 3, 6, and 12 months) (gridded temperature percentile maps for the last 1, 3, and 6 months) (Leaky Bucket model temperature percentile map).
Monthly streamflow was mostly near normal. Snow has melted out of low elevations (but remains in the higher mountains); the surface layers of the ground have thawed in most areas, while deeper layers are still frozen. Satellite observations of vegetative health (stressed vegetation, drought stress, VHI) 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 dryness was occurring at shallow depths.
Areas of abnormal dryness were in the southern Panhandle, Cook Inlet, and central to northeast interior regions. Moderate drought developed in northeast Alaska in the Yukon Flats, covering about 1.2% of the state on the July 2, 2024 USDM map.
Puerto Rico and U.S. Virgin Islands
June 2024 was mostly wetter than normal across Puerto Rico (PR) and the U.S. Virgin Islands (USVI). Wetter-than-normal conditions dominated the 2- to 4-month time periods. Drier-than-normal areas were evident at 12 months, especially in northwest PR (radar-based precipitation anomaly estimates for the last 1, 2, 3, 4 months) (low elevation station precipitation anomaly maps for the last 1, 2, 3, 4, 12 months) (climate engine model percent of normal precipitation map for the last month: PR and USVI, Caribbean and Gulf of Mexico region).
Temperatures were generally warmer than normal for June and much of the last 12 months (low elevation station precipitation anomaly maps for the last 1, 2, 3, 4, 12 months). Root zone analysis indicated that soil conditions were dry across the southern coast of PR, with dryness more evident in the mid-level and deeper soil layers compared to shallower soil layers (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 few if any areas of stressed vegetation. Monthly streamflow on PR showed near- to above-normal stream levels. In the USVI, groundwater levels generally declined during June on St. John and St. Thomas, but held steady on St. Croix. The end-of-June groundwater level was at the middle third of the recent historical record on St. Croix, but was in the upper third at St. John and St. Thomas.
PR and the USVI continued free of drought and abnormal dryness on the July 2, 2024 USDM map.
CONUS State Precipitation Ranks
June 2024 was drier than normal across much of the CONUS east of the Mississippi River, much of the West (except the Southwest), and parts of the Plains, with record dryness occurring locally in the Mid-Atlantic, Southeast, and southern parts of California and Nevada. Nineteen states had a precipitation rank in the driest third of the historical record for June. Three ranked in the top ten driest category — Virginia (driest June on record), North Carolina (second driest), and Georgia (fourth driest). Four states came close — Wyoming (11th driest), South Carolina (12th driest), West Virginia (12th driest), and Tennessee (13th driest).
April-June 2024 was drier than normal across much of the West, the Mid-Atlantic, and parts of the Northeast, Southeast, Ohio Valley, and Plains, with record dryness occurring locally in the Rio Grande Valley. Eleven states had a precipitation rank in the driest third of the historical record for April-June. None ranked in the top ten driest category, but two came close — North Carolina and Nevada (both 15th driest).
Parts of the CONUS have had very dry conditions at various times during the past 6 to 12 months, but the location of the dryness varied and some of the dry areas had wetter-than-normal conditions during intermittent months (low elevation station precipitation anomaly maps for the last 6, 9, and 12 months) (climate division precipitation rank maps for the last 6 and 12 months) (gridded precipitation percentile maps for the last 6 months). Persistently dry areas include parts of the Plains (especially the Rio Grande Valley), Pacific Northwest, Ohio Valley, and East Coast. Those states that were dry experienced enough precipitation over other parts of the state to balance out the dryness. So, only one state ranked in the driest third of the 1895-2024 record for January-June and four were in the driest third of the historical record for July-June; no state ranked in the top 10 driest category for these two time periods.
Agricultural Belts
During June 2024, the Primary Corn and Soybean agricultural belt was mostly warmer than normal and generally wetter than normal in the north and west to drier than normal in the east and south. The month ranked as the 49th wettest and 25th warmest June, regionwide, in the 1895-2024 record.
March marks the beginning of the growing season for the Primary Corn and Soybean belt. March-June 2024 was warmer and mostly wetter than normal. The period ranked as the sixth warmest and 13st wettest March-June, regionwide, in the historical record.
According to the U.S. Department of Agriculture (USDA), as of July 2, 2024, drought affected approximately 26% of barley production, 7% of corn production, 19% of cotton production, 19% of sorghum production, 9% of soybean production, 6% of spring wheat production, 19% of winter wheat production, 17% of hay acreage, 14% of the cattle inventory, 10% of the milk cow inventory, and 17% of the sheep inventory. Most of these (except for sorghum and winter wheat) are higher than they were last month.
Based on June 30 USDA statistics, 15% of the nation's winter wheat crop, 9% of the corn crop, 8% of the soybean crop, 4% of the spring wheat crop, and 23% of the pasture and rangeland were in poor to very poor condition, and 28% of the nation's topsoil and 28% of the subsoil were short or very short of moisture (dry or very dry). States with the driest soils were in the Mid-Atlantic to Southeast plus Nevada and Mexico, followed by several other states in the West, central to southern Plains, and Ohio to Lower Mississippi Valleys.
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), June 2024 was drier than normal in the Republic of Palau and parts of the Marshalls and FSM, but near to wetter than normal in American Samoa, the Marianas, and other parts of the FSM and Marshalls.
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 western and southern parts of the FSM and the northern Marshalls. June precipitation was above the monthly minimums in American Samoa, Palau, the Marianas, and most of the FSM and Marshalls. 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 June 2024, which is in the wet season for Palau, Guam, and much of the FSM, and in the dry season for American Samoa. Precipitation was above the monthly minimum but below normal (1981-2010 normal), because the normals are high, at:
- Jaluit: June 2024 precipitation 9.11 inches, June normal mean 10.37 inches.
In the table below, the station identified as Koror is Palau International Airport (Airai).
| Station Name | Jul 2023 | Aug 2023 | Sep 2023 | Oct 2023 | Nov 2023 | Dec 2023 | Jan 2024 | Feb 2024 | Mar 2024 | Apr 2024 | May 2024 | Jun 2024 | Jul- Jun |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chuuk | 130% | 118% | 112% | 110% | 141% | 100% | 100% | 76% | 40% | 99% | 95% | 132% | 102% |
| Guam NAS | 86% | 132% | 98% | 152% | 84% | 107% | 59% | 62% | 78% | 283% | 112% | 129% | 95% |
| Kapingamarangi | 162% | 121% | 256% | 117% | 153% | 74% | 188% | 206% | 196% | 99% | 95% | 48% | 123% |
| Koror | 145% | 125% | 130% | 108% | 85% | 67% | 136% | 140% | 48% | 184% | 59% | 98% | 102% |
| Kosrae | 132% | 104% | 123% | 153% | 163% | 44% | 90% | 119% | 96% | 84% | 124% | 109% | 92% |
| Kwajalein | 45% | 81% | 61% | 103% | 156% | 111% | 53% | 52% | 196% | 80% | 166% | 147% | 98% |
| Lukonor | 75% | 74% | 115% | 136% | 81% | 94% | 64% | 76% | 153% | 164% | 150% | 113% | 94% |
| Majuro | 70% | 95% | 56% | 86% | 101% | 70% | 57% | 74% | 16% | 111% | 150% | 99% | 84% |
| Pago Pago | 102% | 42% | 156% | 91% | 36% | 195% | 142% | 201% | 71% | 115% | 211% | 186% | 117% |
| Pohnpei | 148% | 219% | 156% | 83% | 178% | 48% | 50% | 170% | 91% | 116% | 121% | 104% | 119% |
| Saipan | 46% | 142% | 109% | 92% | 133% | 158% | 74% | 79% | 83% | 67% | 53% | 213% | 104% |
| Yap | 168% | 145% | 70% | 88% | 79% | 41% | 90% | 55% | 14% | 33% | 77% | 55% | 84% |
| Station Name | Jul 2023 | Aug 2023 | Sep 2023 | Oct 2023 | Nov 2023 | Dec 2023 | Jan 2024 | Feb 2024 | Mar 2024 | Apr 2024 | May 2024 | Jun 2024 | Jul- Jun |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chuuk | 15.56" | 15.23" | 13.07" | 12.70" | 14.93" | 11.22" | 10.05" | 5.49" | 3.30" | 12.38" | 10.76" | 15.38" | 140.07" |
| Guam NAS | 8.69" | 19.47" | 12.46" | 17.40" | 6.18" | 5.49" | 2.38" | 1.88" | 1.62" | 7.17" | 3.82" | 8.00" | 94.56" |
| Kapingamarangi | 22.86" | 9.87" | 25.45" | 9.55" | 14.14" | 7.33" | 17.18" | 19.05" | 22.43" | 13.53" | 11.42" | 6.59" | 179.4" |
| Koror | 26.81" | 16.86" | 15.26" | 12.80" | 9.65" | 7.46" | 13.85" | 11.97" | 3.56" | 13.44" | 7.01" | 17.05" | 155.72" |
| Kosrae | 19.67" | 14.72" | 17.52" | 16.79" | 22.60" | 7.06" | 15.04" | 15.43" | 15.34" | 14.64" | 21.96" | 16.03" | 196.8" |
| Kwajalein | 4.45" | 7.86" | 6.60" | 11.46" | 17.65" | 7.42" | 1.66" | 1.37" | 4.61" | 4.19" | 11.17" | 10.17" | 88.61" |
| Lukonor | 11.89" | 10.33" | 11.63" | 15.43" | 7.40" | 10.54" | 5.42" | 6.83" | 14.20" | 18.58" | 17.54" | 13.12" | 142.91" |
| Majuro | 7.87" | 11.07" | 6.27" | 10.98" | 13.51" | 7.96" | 4.38" | 5.11" | 1.08" | 10.43" | 15.17" | 10.92" | 104.75" |
| Pago Pago | 5.64" | 2.26" | 10.18" | 8.45" | 3.69" | 25.00" | 18.99" | 24.09" | 7.61" | 10.83" | 20.37" | 9.91" | 147.02" |
| Pohnpei | 22.76" | 31.21" | 19.57" | 12.71" | 26.39" | 7.76" | 6.65" | 16.27" | 12.02" | 21.36" | 24.07" | 15.34" | 216.11" |
| Saipan | 4.13" | 18.62" | 11.03" | 9.80" | 7.44" | 6.07" | 1.87" | 2.05" | 1.57" | 1.76" | 1.26" | 7.71" | 73.31" |
| Yap | 25.35" | 21.43" | 9.46" | 10.74" | 6.95" | 3.53" | 5.73" | 2.84" | 0.64" | 1.83" | 6.03" | 6.61" | 101.14" |
| Station Name | Jul 2023 | Aug 2023 | Sep 2023 | Oct 2023 | Nov 2023 | Dec 2023 | Jan 2024 | Feb 2024 | Mar 2024 | Apr 2024 | May 2024 | Jun 2024 | Jul- Jun |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chuuk | 11.98" | 12.86" | 11.71" | 11.51" | 10.61" | 11.25" | 10.10" | 7.25" | 8.32" | 12.47" | 11.30" | 11.66" | 136.77" |
| Guam NAS | 10.14" | 14.74" | 12.66" | 11.44" | 7.38" | 5.11" | 4.01" | 3.03" | 2.07" | 2.53" | 3.40" | 6.18" | 99.09" |
| Kapingamarangi | 14.15" | 8.13" | 9.93" | 8.19" | 9.27" | 9.84" | 9.15" | 9.27" | 11.43" | 13.64" | 12.08" | 13.78" | 145.85" |
| Koror | 18.53" | 13.50" | 11.77" | 11.84" | 11.39" | 11.16" | 10.18" | 8.56" | 7.44" | 7.32" | 11.83" | 17.48" | 152.90" |
| Kosrae | 14.91" | 14.22" | 14.22" | 10.94" | 13.83" | 16.11" | 16.67" | 12.93" | 16.06" | 17.51" | 17.75" | 14.64" | 213.87" |
| Kwajalein | 9.87" | 9.74" | 10.74" | 11.18" | 11.28" | 6.66" | 3.16" | 2.64" | 2.35" | 5.26" | 6.72" | 6.93" | 90.41" |
| Lukonor | 15.93" | 14.04" | 10.15" | 11.32" | 9.08" | 11.27" | 8.41" | 8.93" | 9.26" | 11.31" | 11.69" | 11.65" | 151.36" |
| Majuro | 11.17" | 11.69" | 11.17" | 12.73" | 13.44" | 11.39" | 7.74" | 6.88" | 6.58" | 9.42" | 10.11" | 11.01" | 125.25" |
| Pago Pago | 5.55" | 5.38" | 6.53" | 9.26" | 10.14" | 12.84" | 13.34" | 12.00" | 10.68" | 9.39" | 9.66" | 5.33" | 125.57" |
| Pohnpei | 15.43" | 14.26" | 12.55" | 15.27" | 14.83" | 16.08" | 13.18" | 9.55" | 13.17" | 18.41" | 19.96" | 14.81" | 182.36" |
| Saipan | 8.91" | 13.13" | 10.09" | 10.62" | 5.61" | 3.85" | 2.53" | 2.59" | 1.89" | 2.63" | 2.38" | 3.62" | 70.25" |
| Yap | 15.08" | 14.82" | 13.50" | 12.18" | 8.83" | 8.51" | 6.39" | 5.19" | 4.56" | 5.63" | 7.85" | 12.04" | 120.31" |
As measured by percent of normal precipitation, Yap was drier than normal at all time scales in the short term (June and the last 3 months [April-June]) and long term (year to date [January-June] and last 12 months [July 2023-June 2024]). Kapingamarangi was drier than normal in the short term and near to wetter than normal in the long term. Guam, Kosrae, and Majuro were drier than normal in the long term and near to wetter than normal in the short term. Airai was drier than normal for the last 3 months and year to date but near normal for June and the last 12 months. Chuuk and Saipan were drier than normal for the year to date but near to wetter than normal for the other 3 time periods. Lukunor was drier than normal for the last 12 months but wetter than normal for the other 3 time periods. Kwajalein, Pago Pago, and Pohnpei were near to wetter than normal for all 4 time periods.
Based on percent of normal average (instead of normal median values), in the Marianas Islands, June and the last 2 months were wetter than normal across the main islands, with a mixed precipitation anomaly pattern for the 3- to 4-month time periods and a drier-than-normal pattern dominating at 12 months (percent of normal precipitation maps for the last 1, 2, 3, 4, 12 months).
Based on percent of normal average (instead of normal median values), the Marshall Islands were mostly drier than normal in June, with a mixed anomaly pattern for the last 2 months and drier-than-normal conditions dominating at the 3- to 12-month time scales (percent of normal precipitation maps for the last 1, 2, 3, 4, 12 months).
According to the June 30 USDM produced for the USAPI:
- In the Marianas, drought improved to abnormal dryness on Saipan, Guam, and Rota;
- In the FSM, extreme drought improved to moderate drought on Ulithi and extreme drought improved to severe drought on Yap, three stations had insufficient data for an analysis, and the rest of the FSM was free of drought or abnormal dryness;
- In the Marshalls, moderate drought worsened to severe drought at Wotje, abnormal dryness ended at Kwajalein, and abnormal dryness reappeared for one week at Jaluit before disappearing again; and
- Abnormal dryness ended at Palau.
The level of the reservoir on Majuro began the month at 33.1 million gallons, fluctuated up and down to a peak of 33.9 million gallons on the 10th, dropped to 32.0 million gallons on the 14th, then generally held steady for the rest of June, ending the month at 31.9 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) revealed areas of stressed vegetation remaining on Guam.
The National Weather Service (NWS) office in Guam issued two Drought Information Statements (DGT) for drought for June (on June 7 and 21) and one in early July. Drought impacts included:
- Gitman Reservoir on Yap Proper had low water levels early in June (near or below levels recorded during the 2016 drought);
- showers in June brought some relief to Yap State and the northern RMI, but water shortages still lingered;
- agricultural strain was reported in early June from assessment teams and residents from islands across Yap State: taro patches drying up, coconuts drying out, and many reports of yellowing crops; the agricultural strain improved by early July with vegetation becoming greener.
June 2024 precipitation ranks ranged from dry to wet with some mid-range, based on data available at the time of this report. Some locations have had dry conditions for several months:
- Yap: sixth driest June (in a 73-year record), third or fourth driest May-June back through September-June (all 9 time periods), 14th driest July-June (12-month period).
- Wotje: eighth driest June (40 years), August-June, and July-June.
- Nukuoro: fifth driest June (42 years), sixth driest May-June, and third driest February-June.
- Kapingamarangi: eighth driest June (34 years) and May-June, but second wettest July-June.
- Jaluit: fourth driest 12-month period July-June (38 years), but only 17th driest June.
- Ulithi: seventh driest November-June (36 years) but ninth wettest June.
At the wet end of the scale:
- Saipan had the fourth wettest June (44 years).
- Pago Pago had the second wettest December-June (58 years) and November-June.
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 June 2024, January-June 2024 (last 6 months), and July 2023-June 2024 (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 | June 2024 | Jan-Jun 2024 | Jul 2023-Jun 2024 | Period of Record | |||
|---|---|---|---|---|---|---|---|
| Rank | Years | Rank | Years | Rank | Years | ||
| Ailinglaplap | 30 | 41 | 27 | 41 | 23 | 38 | 1981-2024 |
| Airai | 45 | 73 | 32 | 73 | 44 | 72 | 1951-2024 |
| Chuuk | 62 | 73 | 22 | 73 | 33 | 73 | 1951-2024 |
| Fananu | -- | 9 | -- | 4 | -- | 3 | 2003-2023 |
| Guam | 53 | 68 | 30 | 67 | 27 | 67 | 1957-2024 |
| Jaluit | 17 | 40 | 11 | 40 | 4 | 38 | 1981-2024 |
| Kapingamarangi | 8 | 34 | 24 | 28 | 20 | 21 | 1962-2024 |
| Kosrae | 30 | 57 | 15 | 46 | 16 | 38 | 1954-2024 |
| Kwajalein | 48 | 73 | 32 | 72 | 20 | 72 | 1952-2024 |
| Lukunor | 28 | 40 | 32 | 40 | 16 | 27 | 1981-2024 |
| Majuro | 32 | 71 | 13 | 70 | 10 | 70 | 1954-2024 |
| Mili | -- | 39 | -- | 39 | -- | 34 | 1981-2024 |
| Nukuoro | 5 | 42 | 7 | 41 | 13 | 39 | 1981-2024 |
| Pago Pago | 49 | 59 | 56 | 58 | 48 | 58 | 1966-2024 |
| Pingelap | -- | 41 | -- | 37 | -- | 34 | 1981-2024 |
| Pohnpei | 31 | 73 | 38 | 73 | 64 | 73 | 1951-2024 |
| Saipan | 41 | 44 | 17 | 43 | 20 | 35 | 1981-2024 |
| Ulithi | 32 | 40 | 8 | 38 | 21 | 35 | 1981-2024 |
| Utirik | -- | 15 | -- | 9 | -- | 5 | 1985-2020 |
| Woleai | -- | 41 | -- | 32 | -- | 25 | 1968-2024 |
| Wotje | 8 | 40 | 17 | 40 | 8 | 36 | 1981-2024 |
| Yap | 6 | 73 | 4 | 73 | 14 | 73 | 1951-2024 |
SPI values for seven time periods for Pacific Islands, computed by the Honolulu NWS office:
NOAA Regional Climate Centers
More information, provided by the NOAA Regional Climate Centers and others, can be found below.
Southeast
As noted by the Southeast Regional Climate Center, temperatures were above average across most of the Southeast in June. Monthly temperatures were 2 to 4 degrees F (1.1 to 2.2 degrees C) above average across Puerto Rico and the U.S. Virgin Islands. San Juan, PR (1898-2024) recorded its warmest June on record, with the National Weather Service in San Juan issuing excessive heat warnings on a third of the days during the month.
Following a generally wet May, precipitation in June was below average across nearly all of the Southeast region, except across South Florida and parts of southern Alabama and northwest Florida, which were much wetter than average. The driest locations were found across portions of northeast Florida, southern Georgia, and large portions of North Carolina and Virginia. Many locations recorded less than half of their expected monthly total, while some recorded less than a quarter of their expected monthly total. Lynchburg, VA (1893-2024) recorded just 0.04 inch (1 mm) for the month, making it the driest June and third driest month on record. Chapel Hill, NC (1891-2024) also recorded its driest June on record with just 0.47 inch (12 mm), breaking the previous record of 0.54 inch (14 mm) set in 1931. Alma, GA (1948-2024) and Macon, GA (1892-2024) recorded their driest June on record with 0.83 and 0.34 inch (21 and 9 mm), respectively. Valdosta, GA ended a streak of 28 consecutive days without measurable precipitation on the 25th, making it one of the top 10 longest such streaks on record (since 1948). In Puerto Rico, below-average precipitation was found across the northern half of the island, while above-average precipitation was found along the southern half. Precipitation was near average on Saint Croix.
June began with most of the region free of any drought or abnormal dryness, except South Florida, where moderate (D1) and severe (D2) drought covered much of the lower half of the Peninsula. While conditions there improved considerably, due to heavy rain from a frontal boundary and area of low pressure (Invest 90-L), conditions across the rest of the region deteriorated rapidly during the month, especially across Virginia and eastern portions of the Carolinas. According to the North Carolina State Climate Office, the state observed its second largest weekly increase in abnormally dry (D0) conditions (61 percent) in the history of the USDM (i.e., since 2000) from the 11th to the 18th. By the end of the month, moderate (D1) drought had emerged across portions of the northern tier of the region, with a pocket of severe (D2) drought in central Virginia. Areas of moderate (D1) drought also emerged across central and southern portions of Alabama and Georgia, as well as across parts of the Florida Panhandle. By the end of June, over 85 percent of the region was in at least abnormally dry (D0) conditions, up from about 13 percent at the start of the month. In contrast, the Caribbean was free of drought or abnormal dryness in June.
The heat and lack of precipitation negatively impacted many crops in the region. Dryland corn was particularly affected, as moisture deficits emerged during the pollination stage, resulting in stunted growth and poor kernel production. Hot and dry weather during the month delayed the maturity of cotton and peanuts and slowed the growth of hay. As a result, many farmers have only been able to complete one cutting so far this season. With pastures turning brown or going dormant, producers were forced to supplement with hay and feed. Cattle producers were also concerned about heat stress. Hard, dry soils prevented farmers from double cropping across parts of Virginia. The lack of precipitation did allow for ample field work, including the harvest of winter wheat, though some activities, such as herbicide applications, were delayed due to dry and windy conditions. Irrigation use also increased significantly during the month, which mitigated some of the impacts. While many crops showed signs of stress, those planted earlier in the season generally fared better than those planted later, especially corn and soybeans.
South
As explained by the Southern Regional Climate Center, temperatures were above normal in the western portions of the Southern region, where most stations were two to six degrees Fahrenheit above normal, while in the eastern portions of the region temperatures were near normal for June. Precipitation was mixed across the region with patches of above- and below-normal precipitation scattered across the region. Below-normal precipitation was prevalent in West Texas, Western Oklahoma, Northern Arkansas, and much of Tennessee.
During June, 79 percent of the Southern region remained drought free as of July 2nd, according to the USDM. Degradations were common during June across Eastern Oklahoma, Northern Arkansas, Northern Mississippi, Southern Tennessee, and the Big Bend region of Texas. Improvements were notable in Deep South Texas and across the Oklahoma Panhandle, where isolated three-class improvements were noted. As of July 2nd, none of the Southern region was in Exceptional Drought and 2.5 percent was in Extreme Drought. Given a relatively wet spring across much of the region, cotton conditions are better overall than the same time as last year: 95 percent of the cotton crop in Louisiana is rated as Good to Excellent, followed by 75 percent in Arkansas, 69 percent in Oklahoma, 63 percent in Mississippi, 62 percent in Tennessee, and 44 percent in Texas. Tropical Storm Alberto brought significant rainfall to the Galveston area, leading to freshwater flooding, as well as drought improvement in deep south Texas.
Midwest
As described by the Midwest Regional Climate Center, the preliminary average June temperature for the Midwest was 70.2 degrees F (21.2 degrees C), which was 1.2 degrees F (0.7 degrees C) above the 1991-2020 normal, and preliminary June precipitation totaled 5.17 inches (131 mm) for the Midwest, which was 0.63 inch (16 mm) above normal, or 114 percent of normal. Precipitation was above normal across the upper Midwest and Missouri and below normal across the central Midwest and Ohio River Valley. Across the Ohio River Valley, June precipitation was 25-50 percent of normal. Cincinnati, Ohio, tied for the 2nd driest June in 153 years with just 0.8 inch (20.3 mm) of rain. Abnormal dryness and moderate drought expanded across the central and eastern Midwest in June.
Northeast
As summarized by the Northeast Regional Climate Center, an exceptionally hot, mostly drier-than-normal June led to rapidly expanding drought in the Mid-Atlantic and featured multiple rounds of severe weather. The Northeast had its fifth-hottest June on record with an average temperature of 67.9 degrees F, 2.3 degrees F above normal, and received 3.42 inches of precipitation for the month, 78 percent of normal.
The USDM from June 4 showed moderate drought in a sliver of northwestern Maine and abnormal dryness covering nine percent of the Northeast, including northern Maine, part of western New York, southeastern Pennsylvania, southern New Jersey, portions of Delaware, eastern Maryland, and eastern West Virginia. Excessive heat coupled with little precipitation and increased evapotranspiration rates led to further reductions in soil moisture, streamflow, and, in some areas, groundwater levels in the Mid-Atlantic. This resulted in widespread expansion of moderate drought and abnormal dryness during the second half of June. In New York and New England, there was a mix of deterioration and improvement during the month. Abnormal dryness was introduced in places like southeastern New York and parts of interior New England but areas that received beneficial rainfall such as northern Maine and parts of western New York saw a reduction in abnormal dryness. The USDM from June 25 showed 12 percent of the Northeast in drought and 31 percent as abnormally dry. Between June 18 and 25, Maryland's percent area in drought went from five percent to 61 percent. Over the same week, West Virginia's drought coverage expanded from five percent to 59 percent. Several Mid-Atlantic locations registered record-low streamflow and/or groundwater levels during June. A few communities in southeastern Pennsylvania have asked residents to conserve water due to dry conditions. Additionally, in Maryland, the hot, dry weather prompted burn bans to be enacted and caused issues for some farms, with growers relying heavily on irrigation. Reports from the USDA noted that for the week ending June 30, topsoil moisture was rated very short or short for 85 percent of West Virginia, 80 percent of Maryland, and 75 percent of Delaware.
High Plains
As discussed by the High Plains Regional Climate Center, warmer temperatures dominated the southern and western part of the High Plains region, while North Dakota was slightly cooler than normal this month. Precipitation was scattered but mainly occurred in the eastern part of the region. Wyoming missed nearly everything, with some areas having near zero precipitation. Southwestern Colorado was well above normal, potentially hinting that the North American monsoon had begun.
Although Wyoming is typically drier this time of the year, June was nearly bone dry for parts of the state. Several areas received less than 0.10 inch (2.54 mm), which combined with the warm temperatures, led to the intensification of drought conditions. With the outlooks favoring warmer and drier conditions for upcoming months, conditions in the state will need to be monitored.
June was a mixed bag for drought conditions, with a reduction in intensity but an expansion in coverage. The biggest changes occurred in Wyoming and Kansas this month, while the region observed a 12 percent increase in D0 to D4 (abnormally dry to exceptional drought conditions). Western and central Kansas headed into summer in rough shape, with D3 (extreme drought) being reintroduced to the area. Heavy precipitation this month helped alleviate conditions, with up to 2 categories of improvement. Another round of storms impacted the Dodge City area towards the end of the month, which will likely lead to further improvements. Record to near-record warmth and bone-dry conditions in Wyoming led to the rapid expansion of drought in the state. D0 expanded over 39 percent across the central and northern parts of the state, while a stretch of D1 (moderate drought) increased across the eastern border.
West
As summarized by the Western Regional Climate Center, June was marked with record heat across the West, especially in New Mexico, Arizona, Utah, California, and Nevada. Many cities broke records for their warmest June since modern archives began. This heat was accompanied by drier-than-normal conditions across much of the West except for areas in New Mexico and eastern Arizona which found respite in the seasonal North American monsoon that brought record precipitation totals to some areas.
Many areas in the West recorded zero inches of precipitation for the month of June, primarily in the desert regions of the Southwest which include California, Nevada, and western Arizona. Some of these cities are Las Vegas, NV; Yuma, AZ; Reno, NV; San Francisco, CA; Los Angeles, CA; Fresno, CA; and Orland, CA. Areas of Utah, eastern Oregon, and Idaho saw below-average precipitation for the month of June. Some locations are Laketown, UT (1.04 inches below average), Swan Falls, ID (0.6 inch below average), and Baker, OR (0.99 inch below average). On the other hand, New Mexico and eastern Arizona saw a wetter June with some areas setting records for total precipitation.
According to the USDM, the West remains at 19 percent of the region in drought at the end of June. Drought improved in Utah. Additionally, Idaho and Montana no longer have regions of extreme (D3) drought or higher. No areas of drought are in Nevada, California, Utah, or Oregon. The only area with extreme (D3) and exceptional (D4) drought is southern New Mexico.
Alaska summary: Temperatures across Alaska were on average two to five degrees Fahrenheit above normal. Southcentral and southeast Alaska saw drier-than-normal conditions for the month of June. Northway set a record-driest June at zero inches (2.26 inches below normal), Homer recorded its second driest at 0.08 inch (0.79 inches below normal), Juneau recorded 1.54 inches (40 percent of normal), and Sitka recorded 1.31 inches (44 percent of normal). Only one percent of Alaska is in moderate (D1) drought, which is in Yukon-Koyukuk where the Yukon River meets the Upper Mouth.
Hawaii summary: Hawaii saw mostly average temperatures and precipitation for the month of June. The only region of dryness was on the island of O'ahu. Honolulu received 0.06 inch of rain, which is 0.44 inches below normal. By the end of June, Hawaii's percentage of drought had increased to 8.92 percent, only a 0.68 percent increase from May. However, 62 percent of Hawaii is in at least abnormally dry conditions (D0). Areas of moderate (D1) and severe (D2) drought are present in the center of the Big Island and southwestern Maui.