Issued 13 December 2023

November 2023 Palmer Z-Index
U.S. Percent Area Wet or Dry January 1996 - November 2023
November 2023 /monitoring-content/sotc/drought/2023/11/tn-p-reg040dv00elem01-09112023.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

  • 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".
  • U.S. Drought Monitor information is currently unavailable.

Detailed Drought Overview

The upper-level atmospheric circulation over North America during November 2023 was characterized by an overall long-wave high-pressure ridge over the western CONUS and western Canada and a low-pressure trough that was centered over Hudson Bay and extended into New England. This overall pattern produced above-normal temperatures in the north-central part of the CONUS with cooler-than-normal temperatures in the Northeast. The northwesterly flow over the central part of the continent, between the western ridge and eastern trough, funneled drier-than-normal air masses from Canada into the central CONUS. The result was a drier-than-normal month for much of the U.S., with the most extreme dry anomalies over the Plains to Midwest. Several Pacific weather systems (or short-wave troughs) moved through the westerly jet stream flow, frequently distorting the long-wave pattern. Their corresponding cold fronts and surface low pressure systems brought alternating waves of cooler air. Some of them had enough Pacific moisture to bring precipitation to parts of the West, while some tapped Gulf of Mexico and Atlantic moisture to spread precipitation over parts of the eastern CONUS. But in most cases, these precipitation amounts were not enough to exceed monthly normals, so most of the CONUS ended up drier than normal for the month. Ridging in the Caribbean kept Puerto Rico and the U.S. Virgin Islands drier than normal, while Hawaii and Alaska had a mixed precipitation anomaly pattern.

The below-normal precipitation in November led to expansion or intensification of drought or abnormal dryness over parts of the Southwest, Southeast to Mid-Atlantic, and Mid-Mississippi to Ohio Valleys. Above-normal precipitation or a re-evaluation of conditions resulted in contraction or reduction in the intensity of drought in the Pacific Northwest, southern Plains, and parts of the Southeast. Drought contraction exceeded expansion with the USDM-based national moderate-to-exceptional drought footprint across the CONUS decreasing from 36.5% at the end of October to 36.1% at the end of November (from 30.7% to 30.3% for the 50 states and Puerto Rico).

According to the Palmer Drought Index, which goes back to the beginning of the 20th century, about 37.4% of the CONUS was in moderate to extreme drought at the end of November, which is an increase compared to the end of October.

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Drought conditions at the end of November, as depicted on the November 28, 2023 USDM map, included the following core drought and abnormally dry areas:

November 2023 /monitoring-content/sotc/drought/2023/11/20231128_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.

November 2023 Palmer Z-Index
November 2023 PHDI

Used together, the Palmer Z Index and PHDI maps show that short-term drought occurred from the Mississippi River to Appalachian Mountains and in parts of the West, Plains, Southeast, Northeast, and Mid-Atlantic states, expanding or intensifying long-term drought and reducing areas of long-term wet conditions (PHDI maps for November compared to October). Short-term wet conditions occurred in parts of southern Texas and the Florida Peninsula, 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.

November 2023 SPI
October-November 2023 SPI
September-November 2023 SPI
June-November 2023 SPI

The SPI maps illustrate how moisture conditions have varied considerably through time and space over the last two years. Dryness is evident across most of the Mississippi Valley at the 1-, 6-, and 9-month time scales, and in the Mid- to Lower Mississippi Valley at the other time scales. Most of the Northeast is dry at 1 month, and southern or western parts are dry at longer time scales. Parts of the Mid-Atlantic coast are dry at 2-24 months. Parts to most of the Great Lakes are dry at 1- and 3- to 9-month time scales. The Ohio Valley, Tennessee Valley, and southern to central Appalachians are dry from 1 to 9 months, with parts dry at longer time scales. The northern Plains are dry at 1 month, parts of the central Plains are dry at 2 to 24 months, and parts of the southern Plains are dry at 1 and 6-24 months. Parts to most of the Southwest (Four Corners states) are dry at all time scales. Parts of the Pacific Northwest are dry at 2 to 24 months. Parts to much of the West Coast (mainly California) are dry at 1- to 6-month time scales. Wet conditions are evident in parts of the northern Plains at 2 to 24 months, in New England at 6 to 24 months, in western parts of the central Plains at 6 to 12 months, and from California and the Great Basin to central Rockies at 6 to 24 months.

March-November 2023 SPI
December 2022-November 2023 SPI
December 2021-November 2023 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, November marks the end of climatological autumn, which is the season when a lower sun angle results in decreasing evapotranspiration. During November 2023, temperatures were still warmer than normal across much of the CONUS, especially in the central to northern Plains and parts of the Southwest. Drier-than-normal weather occurred across much of the CONUS, but the most widespread driest anomalies occurred in the Midwest (Upper Mississippi and Ohio Valleys), where temperature anomalies were closer to normal, with some very dry anomalies in parts of the northern Plains. The Southwest had a mixture of dry and wet anomalies for November. The result of this pattern of temperature and precipitation anomalies was the November 2023 1-month SPEI having similar magnitudes as the corresponding SPI. At the 2- to 3-month time scales, precipitation was quite dry across the Mid- and Lower Mississippi Valley, Ohio Valley, and Tennessee Valley, but temperature anomalies were only slightly warmer than normal, so the 2- and 3-month SPEI magnitudes there were similar to the corresponding SPI magnitudes. But unusually warm temperatures dominated the Southwest, where it was also drier than normal, so the SPEI was more extreme than the SPI at these time scales in the Southwest. Excessive heat and dryness afflicted much of the Southwest to Gulf of Mexico coast at the 5- to 9-month time scales, resulting in more extreme SPEI values than SPI values (SPEI maps for the last 1, 2, 3, 5, 6, 9, 12 months) (SPI maps for the last 1, 2, 3, 5, 6, 9, 12 months).

The SPEI at the 3- to 12-month time scales was more extreme than the SPI for Louisiana, Arizona, and New Mexico. In some cases, the SPEI was record dry whereas the SPI was not:

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). The central Plains was so dry for the last 2 to 3 years that the SPI is more extreme than the corresponding SPEI in spite of temperatures being above normal. But in the southern Plains the heat dominated the dryness, so the SPEI is more extreme than the SPI there. 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 24, 36, 48, 60, 72 months) (SPI maps for last 24, 36, 48, 60, 72 months).

Regional Discussion

Mississippi River Basin

November 2023 was especially dry across the Mississippi River and its tributaries. Drought has occurred in several tributary basins for the last 4 years. Dry conditions were especially acute in the Ohio and Upper Mississippi Basins during this spring and summer. The combination of dry conditions for the last 2 to 4 years in the Missouri Basin, and this year in the Upper Mississippi, Ohio, and recently in the Tennessee Basins, has resulted in record to near-record low flows in parts of the Mississippi River that caused barges to run aground. To make matters worse, the low flows upstream were compounded by a very hot and dry summer in the Lower Mississippi Basin, consequently leading to saltwater intrusion concerns in southern Louisiana.

For the Upper Mississippi River Basin, November 2023 ranked as the fourth driest November in the 1895-2023 record. May-November 2023 was the fifth driest such 7-month period and March-November 2023 was the seventh driest such 9-month period. According to the USDM, 53.0% of the basin was in moderate to extreme drought at the end of November, which is more than last month but down from a peak of 85.9% which occurred on July 11. Based on the Palmer Drought Index, 81.0% of the basin was in moderate to extreme drought at the end of November. This is the highest value this year and is approaching the peak value of the 2012 drought.

The Ohio River Basin had the eighth driest November and seventh driest September-November in the 129-year historical record. According to the USDM, 36.5% of the basin was in moderate to extreme drought at the end of November, which is more than last month and is approaching the recent peak of 37.2% which occurred on October 17 (the 2023 peak of 46.4% occurred on June 13). Based on the Palmer Drought Index, 20.5% of the basin was in moderate to extreme drought at the end of November. This is the highest value this year.

Dry conditions continued in the Tennessee River Basin, with November ranking 16th driest and September-November 2023 ranking as the second driest such 3-month period on record. According to the USDM, 96.6% of the basin was in moderate to extreme drought at the end of November, which is more than last month and is the highest value this year. Based on the Palmer Drought Index, 60.4% of the basin was in moderate to extreme drought at the end of November. This is also the highest value this year.

Some rain fell in the Lower Mississippi River Basin this month, but November 2023 was still the 21st driest November on record. Both August-November 2023 and May-November 2023 ranked as the sixth driest such 4-month and 7-month, respectively, periods on record. Excessive heat also characterized much of 2023, with January-November 2023 ranking as the warmest such year-to-date on record. According to the USDM, 82.4% of the Lower Mississippi Basin was in moderate to exceptional drought at the end of November, which is more than last month but less than the peak of 87.3% that occurred on October 24. Based on the Palmer Drought Index, 55.8% of the basin was in moderate to extreme drought at the end of November. This is the highest value this year.

Rio Grande River Basin

The Rio Grande River Basin has been unusually dry and hot this year. Recent rainfall has moderated the precipitation ranks, but June-November still ranked ninth driest and December-November tenth driest on record. Every period from August-November back to April-November ranked warmest on record, and the trend for April-November temperatures has been increasing at an accelerating pace since the 1990s. According to the USDM, 82.0% of the basin was in moderate to exceptional drought, which is less than last month. Based on the Palmer Drought Index, 98.4% of the basin was in moderate to extreme drought at the end of November, which also is a little less than last month. Both the PDSI and USDM show that the Rio Grande Basin has been in cyclical drought for the last 23 years. The Palmer Drought Index reveals that the basin has experienced frequent drought for the last 123 years, especially in the 1950s and since 2000.

Hawaii

November 2023 had a mixed precipitation anomaly pattern over the Hawaiian Islands. Drier conditions were evident at longer time scales, with drier-than-normal conditions dominating at 2 to 6 months. Oahu to Maui were mostly drier than normal, with the other main islands having a mixed precipitation anomaly pattern, at 8- to 9-month time scales. A mixed anomaly pattern dominated at 11 and 12 months (precipitation anomaly maps for the last 1, 2, 3, 5, 6, 8, 9, 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 on Maui. Based on satellite analyses (stressed vegetation, drought stress, VHI), vegetation was stressed across the main islands.

Moderate to extreme drought continued across Hawaii during November, with the drought area growing slightly, compared to the end of October, to cover about 93.6% of the state on the November 28, 2023 USDM map.

Alaska

November 2023 was near to wetter than normal across most of Alaska, except for some drier-than-normal conditions in southwestern Alaska and some eastern interior stations. Dryness in the southwest persisted at the 2- to 3-month time scales. The last 5 to 12 months were drier than normal at scattered stations from the south coastal to interior regions and in the Aleutians and southern panhandle, but wetter-than-normal conditions otherwise dominated (low elevation station precipitation anomaly maps for the last 1, 2, 3, 5, 6, 8, 9, 11, 12 months) (high elevation SNOTEL station precipitation percentile maps for the last 1, 3, and 12 months) (SNOTEL basin and station percent of normal precipitation maps for the last 1, 3, and 12 months) (climate division precipitation rank maps for the last 1, 3, 6, 11, and 12 months) (climate engine model percent of normal precipitation map for the last month) (Leaky Bucket model precipitation percentile map).

November temperatures were warmer than normal across the state. This pattern persisted at the 3- to 6-month time scale. Warmer-than-average temperatures dominated at longer time scales, when compared to the long-term (1926-2022) average. But when compared to more recent (1991-2020) normals, near to cooler-than-normal temperatures were evident at some western to central stations because of a pronounced warming trend in recent decades (low elevation station temperature anomaly maps for the last 1, 2, 3, 11, 12 months) (climate division temperature rank maps for the last 1, 3, 6, 11, and 12 months) (gridded temperature percentile maps for the last 1, 3, and 11 months) (Leaky Bucket model temperature percentile map).

Monthly streamflow was mostly near to above normal for those streams that haven't yet 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 some dryness was occurring in parts of the southeast and northeast.

Dryness disappeared this month so Alaska was free of drought or abnormal dryness on the November 28, 2023 USDM map.

Puerto Rico and U.S. Virgin Islands

November 2023 was drier than normal across most of Puerto Rico (PR) and the U.S. Virgin Islands (USVI). A mixed precipitation anomaly pattern was evident at 2 months, but drier-than-normal conditions dominated at the 3- to 12-month time scales (radar-based precipitation anomaly estimates for the last 1, 2, 3, 6, 11, and 12 months) (low elevation station precipitation anomaly maps for the last 1, 2, 3, 5, 6, 8, 9, 11, 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 consistently warmer than normal for the last 12 months, with record to near-record warmth during the summer to fall (low elevation station temperature anomaly maps for the last 1, 3, 12 months). San Juan, PR had the warmest November in the 1898-2023 record. In fact, all of the time periods from November back to March-November set a new record or tied a previous record for warmth. Rohlsen Airport on St. Croix had the warmest November in the 1951-2023 record. All of the time periods from November back to August-November were record warm. The excessive heat increased evapotranspiration which made the dry conditions worse.

Root zone analyses indicated that soil conditions were dry along the southwestern and northwestern coasts of PR and in the eastern interior (root zone soil saturation fraction). 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 on PR and the USVI. Monthly streamflow on PR showed below-normal streams in western and northeastern areas. In the USVI, beneficial rains during the last couple months contributed to rising groundwater levels during November at St. John and St. Croix. Groundwater data for St. Thomas was not available this month. The end-of-November groundwater level continued well in the bottom third of the historical record at St. Croix, but was in the upper third at St. John.

In the USVI, long-term severe drought (D2) improved to moderate drought (D1) on St. Croix, and St. John continued free of drought and abnormal dryness. A particularly dry November changed long-term severe drought to short- and long-term severe drought on St. Thomas. On PR, moderate drought shrank slightly to cover about 2.1% of the territory on the November 28, 2023 USDM map.

CONUS State Precipitation Ranks

November 2023 was drier than normal across much of the CONUS from the Mississippi River to the East Coast, and parts of the Plains and West, with record dryness locally in parts of the Midwest. Thirty-three states had a precipitation rank in the driest third of the 129-year historical record for November, including five that ranked in the top ten driest category — Indiana (third driest); Illinois, Missouri, and Wisconsin (each eighth driest); and Kentucky (tenth driest) — and one that was close: Iowa (11th driest).

September-November 2023 was drier than normal across much of the CONUS from the Mississippi River to the East Coast, much of the central to southern Plains, the Four Corners states, and the West Coast, with record dryness locally in parts of the Tennessee Valley. Twenty-six states had a precipitation rank in the driest third of the 1895-2023 historical record for September-November, including four that ranked in the top ten driest category — Tennessee (third driest), Mississippi (eighth driest), Kentucky (ninth driest), and Indiana (tenth driest) — and two that were close: Louisiana (11th driest) and Ohio (13th driest).

June-November 2023 was drier than normal across the Mississippi, Ohio, and Tennessee valleys, much of the Southwest and southern Plains, and parts of the Mid-Atlantic states and West Coast. Twenty-one states had a precipitation rank in the driest third of the historical record for June-November, including six that ranked in the top ten driest category — Louisiana (second driest), Arizona (sixth driest), New Mexico (eighth driest), Iowa and Minnesota (both ninth driest), and Mississippi (tenth driest).

January-November 2023 was drier than normal across the Mississippi, Ohio, and Tennessee valleys, much of the Southwest and southern Plains, along the Gulf of Mexico coast, and in parts of the Mid-Atlantic states and Pacific Northwest, with record dryness occurring locally in the South. Eighteen states had a precipitation rank in the driest third of the historical record for January-November, including two that ranked in the top ten driest category — Louisiana (seventh driest) and Maryland (eighth driest).

December 2022-November 2023 was drier than normal across the Mississippi, Ohio, and Tennessee valleys, parts of the Southwest and southern Plains, along the Gulf of Mexico coast, and in parts of the Mid-Atlantic states and Pacific Northwest. Nineteen states had a precipitation rank in the driest third of the historical record for December-November. None ranked in the top ten driest category, but one was close — Louisiana (11th driest).

Agricultural Belts

During November 2023, the Primary Hard Red Winter Wheat agricultural belt was mostly warmer and drier than normal. The month ranked as the 51st driest and 20th warmest November, regionwide, in the 1895-2023 record.

October marks the beginning of the growing season for the Primary Hard Red Winter Wheat belt. October-November 2023 was mostly warmer and drier than normal, with some wet conditions in the far north and south sections. The period ranked as the 65th driest (65th wettest) and 16th warmest October-November, regionwide, on record.

According to the U.S. Department of Agriculture (USDA), as of November 28, 2023, drought affected approximately 20% of barley production, 44% of corn production, 45% of cotton production, 43% of sorghum production, 47% of soybean production, 29% of spring wheat production, 38% of winter wheat production, 36% of hay acreage, 37% of the cattle inventory, 23% of the milk cow inventory, and 29% of the sheep inventory. Based on November 26 USDA statistics, 15% of the nation's winter wheat crop was in poor to very poor condition, and 41% of the nation's topsoil and 50% of the subsoil were short or very short of moisture (dry or very dry).

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), November 2023 was drier than normal in American Samoa, Palau, and parts of the Marianas and FSM, but near to wetter than normal in southern and eastern Micronesia.

Monthly precipitation amounts were below the monthly minimum needed to meet most water needs (4 inches in the Marianas and Pago Pago, and 8 inches elsewhere) at Pago Pago (American Samoa); Lukunor, Ulithi, and Yap (FSM), and Wotje in the Marshalls. November precipitation was above the monthly minimums at the rest of the stations across the USAPI. The 4- and 8-inch thresholds are important because, if monthly precipitation falls below the threshold, then water shortages or drought become a concern.

The tropical Pacific climatology can experience extremes in precipitation, from very low precipitation during the dry season to very high precipitation during the wet season. This can result in monthly normal precipitation values that are different from the monthly minimum needed to meet most water needs, and this can lead to percent of normal values that seem odd. This was the case during November 2023, which is in the wet season for American Samoa, the Marianas, and the Marshall Islands, and in the dry season for stations in central and southeastern FSM.

Precipitation was above the monthly minimum but below normal (1981-2010 normal), because the normals are high, at:

  • Airai: November 2023 precipitation 9.65 inches, November normal mean 11.90 inches, November normal median 11.39 inches.
  • Guam: November 2023 precipitation 6.18 inches, November normal mean 9.17 inches, November normal median 7.38 inches.
  • Pingelap: November 2023 precipitation 9.75 inches, November normal mean 13.08 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 Dec
2022
Jan
2023
Feb
2023
Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec-
Nov
Chuuk116%92%215%85%137%191%118%130%118%112%110%141%124%
Guam NAS182%350%188%263%198%916%146%86%132%98%152%84%145%
Kapingamarangi53%166%47%116%141%137%145%162%121%256%117%153%121%
Koror105%187%102%185%77%165%77%145%125%130%108%85%113%
Kosrae99%131%188%67%120%87%166%132%104%123%153%163%105%
Kwajalein88%224%50%189%188%345%143%45%81%61%103%156%121%
Lukonor54%124%68%96%77%61%116%75%74%115%136%81%78%
Majuro90%157%138%169%151%102%105%70%95%56%86%101%103%
Pago Pago71%114%110%106%152%168%109%102%42%156%91%36%92%
Pohnpei74%136%146%109%141%145%121%148%219%156%83%178%134%
Saipan130%441%118%138%192%225%92%46%142%109%92%133%123%
Yap131%133%118%137%104%131%121%168%145%70%88%79%114%
Pacific Island Precipitation (Inches)
Station Name Dec
2022
Jan
2023
Feb
2023
Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec-
Nov
Chuuk13.00"9.34"15.60"7.09"17.14"21.57"13.73"15.56"15.23"13.07"12.70"14.93"168.96"
Guam NAS9.32"14.02"5.69"5.45"5.01"31.15"9.00"8.69"19.47"12.46"17.40"6.18"143.84"
Kapingamarangi5.23"15.23"4.37"13.24"19.19"16.59"20.04"22.86"9.87"25.45"9.55"14.14"175.76"
Koror11.76"19.04"8.74"13.74"5.60"19.53"13.44"26.81"16.86"15.26"12.80"9.65"173.23"
Kosrae15.95"21.87"24.25"10.81"21.08"15.41"24.30"19.67"14.72"17.52"16.79"22.60"224.97"
Kwajalein5.88"7.08"1.32"4.43"9.87"23.18"9.93"4.45"7.86"6.60"11.46"17.65"109.71"
Lukonor6.06"10.45"6.08"8.92"8.68"7.13"13.55"11.89"10.33"11.63"15.43"7.40"117.55"
Majuro10.30"12.14"9.51"11.12"14.23"10.35"11.56"7.87"11.07"6.27"10.98"13.51"128.91"
Pago Pago9.10"15.19"13.19"11.34"14.25"16.19"5.81"5.64"2.26"10.18"8.45"3.69"115.29"
Pohnpei11.86"17.94"13.99"14.29"25.90"29.02"17.94"22.76"31.21"19.57"12.71"26.39"243.58"
Saipan5.01"11.16"3.05"2.61"5.05"5.35"3.34"4.13"18.62"11.03"9.80"7.44"86.59"
Yap11.17"8.51"6.11"6.26"5.86"10.28"14.59"25.35"21.43"9.46"10.74"6.95"136.71"
Pacific Island 1981-2010 Normal Median Precipitation (Inches)
Station Name Dec
2022
Jan
2023
Feb
2023
Mar
2023
Apr
2023
May
2023
Jun
2023
Jul
2023
Aug
2023
Sep
2023
Oct
2023
Nov
2023
Dec-
Nov
Chuuk11.25"10.10"7.25"8.32"12.47"11.30"11.66"11.98"12.86"11.71"11.51"10.61"136.77"
Guam NAS5.11"4.01"3.03"2.07"2.53"3.40"6.18"10.14"14.74"12.66"11.44"7.38"99.09"
Kapingamarangi9.84"9.15"9.27"11.43"13.64"12.08"13.78"14.15"8.13"9.93"8.19"9.27"145.85"
Koror11.16"10.18"8.56"7.44"7.32"11.83"17.48"18.53"13.50"11.77"11.84"11.39"152.90"
Kosrae16.11"16.67"12.93"16.06"17.51"17.75"14.64"14.91"14.22"14.22"10.94"13.83"213.87"
Kwajalein6.66"3.16"2.64"2.35"5.26"6.72"6.93"9.87"9.74"10.74"11.18"11.28"90.41"
Lukonor11.27"8.41"8.93"9.26"11.31"11.69"11.65"15.93"14.04"10.15"11.32"9.08"151.36"
Majuro11.39"7.74"6.88"6.58"9.42"10.11"11.01"11.17"11.69"11.17"12.73"13.44"125.25"
Pago Pago12.84"13.34"12.00"10.68"9.39"9.66"5.33"5.55"5.38"6.53"9.26"10.14"125.57"
Pohnpei16.08"13.18"9.55"13.17"18.41"19.96"14.81"15.43"14.26"12.55"15.27"14.83"182.36"
Saipan3.85"2.53"2.59"1.89"2.63"2.38"3.62"8.91"13.13"10.09"10.62"5.61"70.25"
Yap8.51"6.39"5.19"4.56"5.63"7.85"12.04"15.08"14.82"13.50"12.18"8.83"120.31"

As measured by percent of normal precipitation, Pago Pago was drier than normal at all time scales in the short term (November and the last 3 months [September-November]) and long term (year to date [January-November] and last 12 months [December 2022-November 2023]). Lukunor was drier than normal for 3 of the time periods and near normal for the last 3 months. Yap was drier than normal in the short term and wetter than normal in the long term. Airai, Guam, and Majuro were drier than normal or near normal in the short term and near to wetter than normal in the long term. Chuuk, Kapingamarangi, Kosrae, Kwajalein, Pohnpei, and Saipan 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, November and the last 2 to 3 months had a mixed precipitation anomaly pattern across the main islands. At 5 to 6 months, most stations were drier than normal across the main islands except Guam. Wetter-than-normal conditions dominated at 8 to 12-month time scales (percent of normal precipitation maps for the last 1, 2, 3, 5, 6, 8, 9, 11, 12 months).

Based on percent of normal average (instead of normal median values), in the Marshall Islands, wetter-than-normal conditions dominated in November, but it was mostly drier than normal at the 3- to 6-month time scales. A mixed precipitation anomaly pattern was the rule at 2 and 8-12 months (percent of normal precipitation maps for the last 1, 2, 3, 5, 6, 8, 9, 11, 12 months).

According to the November 30 USDM produced for the USAPI, Tutuila (American Samoa, Wotje (RMI), and Lukunor and Ulithi (FSM) were abnormally dry, while the rest of the USAPI stations were free of drought and abnormal dryness. The level of the reservoir on Majuro increased during early November to reach a peak volume of 35.0 million gallons, then decreased during the last half of the month, ending the month at 31.9 million gallons, which was the minimum for the month. If the reservoir dips below 28.8 million gallons, drought becomes a concern, so there is no issue with drought on Majuro at this time. Satellite observations of vegetative health (drought stress, stressed vegetation, VHI) indicated there were some areas of stressed vegetation on Guam, but little concern for drought in the Marianas.

November 2023 precipitation ranks ranged from very dry to very wet but were mostly in the mid-range between wet and dry, based on data available at the time of this report. Long-term conditions also ranged between dry to very wet:

  • Pago Pago: second driest November (in a 58-year record) and seventh driest October-November.
  • Pingelap: seventh driest November (39 years) and June-November, fifth driest August-November, and sixth driest July-November and May-November.
  • Ulithi: sixth driest November (41 years) but fifth wettest December-November.
  • Wotje: ninth driest November (39 years) and June-November, fifth driest August-November, and sixth driest September-November and July-November.
  • Lukunor: tenth driest November (40 years), seventh driest April-November, and eighth driest December-November.
  • Jaluit: 26th driest (15th wettest) November (40 years) but fifth driest May-November and sixth driest April-November and December-November.

At the wet end of the scale:

  • Mili had the wettest November (40 years), June-November, May-November, January-November, and December-November.
  • Pohnpei had the second wettest November (73 years) and wettest May-November and April-November.
  • Guam had the 25th driest November (67 years) but wettest May-November through December-November.

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.

November 2023 USAPI Precipitation Ranks (1 = driest)
StationNovember 2023Jun-Nov 2023Dec 2022-Nov 2023Period of Record
RankYearsRankYearsRankYears
Ailinglaplap3240273928371981-2023
Airai3073537167711951-2023
Chuuk5873567266721951-2023
Fananu81146--22003-2023
Guam2567406766661957-2023
Jaluit26407396371981-2023
Kapingamarangi2935222218211962-2023
Kosrae5156394324361954-2023
Kwajalein6872227252711952-2023
Lukunor104014278271981-2023
Majuro3870117030691954-2023
Mili4040383835351981-2023
Nukuoro2940323933381981-2023
Pago Pago25895816571966-2023
Pingelap739738--341981-2023
Pohnpei7273717270721951-2023
Saipan3543254331341981-2023
Ulithi641353831351981-2023
Utirik--18--8--41985-2020
Woleai30402531--271968-2023
Wotje93993828351981-2023
Yap2173647253721951-2023
Map of USAPINovember 2023 Precipitation (Inches)
Map of USAPI November 2023 Percent of Normal Precipitation
Map of USAPI September 2023-November 2023 Percent of Normal Precipitation
Map of USAPI January-November 2023 Percent of Normal Precipitation
Map of USAPI December 2022-November 2023 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, November precipitation was below average across much of the Southeast, except Florida, and mean temperatures were variable across the region. The driest locations were found across central Alabama, northern and southern portions of Georgia, and western portions of the Carolinas, where many locations recorded less than half of their expected precipitation for the month. Several locations ended long streaks of consecutive dry days during the month. On the 11th, Daytona Beach, FL ended a streak of 31 consecutive days without measurable precipitation, while Gainesville, FL and Tallahassee, FL ended streaks of 32 consecutive days on the 12th. Precipitation was also below average across Puerto Rico and the U.S. Virgin Islands. Cyril King Airport on Saint Thomas recorded its fifth driest November on record (since 1953) with 1.25 inches (32 mm), which is just 20 percent of normal.

Drought conditions worsened in some locations yet improved in others, yielding relatively little overall change across the Southeast. Extreme (D3) drought expanded across northern portions of Alabama and Georgia and into southwestern North Carolina. Areas of moderate (D1) and severe (D2) drought also expanded across the interior of the region from northern Georgia through western Virginia. A small area of moderate (D1) to extreme (D3) drought persisted across the West Coast of Florida, while small areas of moderate (D1) drought emerged across eastern portions of Virginia. On the other hand, drought conditions improved from extreme (D3) to severe (D2) and moderate (D1) drought across the Shenandoah Valley of Virginia and along the northern Gulf Coast, while small areas of abnormal dryness (D0) and moderate (D1) drought were eliminated across eastern portions of the Carolinas. In the Caribbean, a small area of moderate (D1) drought persisted in northwest Puerto Rico, while pockets of abnormal dryness (D0) persisted in the eastern interior and south coastal parts of the island. Severe (D2) drought persisted on Saint Thomas but improved to moderate (D1) drought on Saint Croix. Saint John remained drought-free.

The lack of precipitation and multiple waves of cool temperatures negatively affected many crops across the region. The most notable impacts included delayed harvesting of peanuts due to hard soils, delayed planting and germination of winter crops, particularly small grains, and reduced pasture growth, resulting in hay shortages and supplemental feed for cattle and livestock. Pecan production was also down in Georgia due in part to a combination of unfavorable weather conditions, including a late spring freeze, hurricane activity, extreme heat, and drought. On the other hand, recent precipitation improved pasture conditions in parts of Georgia and northern Florida and helped in the planting of winter crops and small grains. However, some areas received too much rain, resulting in flooded fields, increased disease pressures, and delayed field work.

South

As explained by the Southern Regional Climate Center, dry conditions led to severe impacts from ongoing and worsening drought across southeast Texas, Louisiana, southeastern Arkansas, Mississippi, and Tennessee. Temperatures were near normal across much of the Southern region during November, but precipitation was generally below normal with isolated areas of well above normal precipitation. State totals for the Southern region were all below normal for November: Tennessee (15th driest, out of 129 years), Arkansas (22nd driest), the Southern region as a whole (22nd driest), Louisiana (32nd driest), Mississippi (33rd driest), Oklahoma (35th driest), and Texas (44th driest). There were three stations in Texas that received no measurable precipitation during the month of November: Plains, near Adrian, and Reese Center.

During November the Southern region saw continued drought and degradation of drought conditions across much of Louisiana, Mississippi, Tennessee, and southeastern Arkansas. Louisiana is particularly hard hit with 71 percent of the state being in Exceptional Drought as of November 28th. Texas on the other hand saw broad improvement of drought conditions across the state with many areas one to two classes of improvement in drought status, though drought persists in central Texas and southeast Texas. Areas experiencing Extreme or Exceptional Drought, according to the USDM, across the Southern region decreased by 2% from October 31st (24 percent) to November 28th (22 percent). Soil moisture rankings, according to the Climate Prediction Center, over the areas experiencing drought were well below the historical 30th percentile values for November and across southern Louisiana and southwestern Mississippi were in the 1st percentile. Ongoing and worsening dry conditions led to wildfires in Tennessee and reported tree deaths in Mississippi, Louisiana, and southeast Texas. Particularly striking were reports of livestock fatalities in Mississippi where cattle became trapped in soil fissures that had opened due to dry conditions. Low flows on the Mississippi River are impacting barge traffic, making grain transport more expensive and requiring expensive and time-intensive dredging to make transit possible.

Midwest

As described by the Midwest Regional Climate Center, November precipitation totaled 0.93 inch (24 mm) for the Midwest, which was 1.61 inches (41 mm) below normal, or 37 percent of normal, and the average November temperature for the Midwest was 39.3 degrees F (4.1 degrees C), which was 0.8 degrees F (0.5 degrees C) above the 1991-2020 normal. Preliminary precipitation rankings indicate the Midwest had the 5th driest November dating back to 1895. Dry conditions affected the entire region, with a large swath of the south-central Midwest achieving 2-4 inches (51-102 mm) of precipitation deficits. Preliminary statewide precipitation totals ranged from 0.75 inch (19 mm) below normal in Michigan to 2.57 inches (65 mm) below normal in Indiana. Preliminary rankings indicate Indiana had the 3rd driest November on record, while Illinois, Iowa, and Missouri all had the 8th driest. Several long-running weather stations across the region had a top five driest November, including Pipestone-MN (1st), Collegeville-MN (1st), Minneapolis-MN (2nd), Paducah-KY (4th), Fort Wayne-IN (5th), and South Bend-IN (5th). Fall (September-November) precipitation for the Midwest totaled 6.4 inches (163 mm), which was 2.66 inches (68 mm) below normal.

Drought conditions expanded during November, with the most notable increases in severity and extent across the lower Midwest. The month concluded with about 74 percent of the Midwest affected by dryness or drought, up nearly 10 percent from the start of the month. Locations across southern Missouri, Illinois, and Kentucky had 2-3 class degradations on the USDM map during November. Drought persisted along and west of the Mississippi River, with a wide swath of extreme (D3) drought parked over eastern Iowa.

Northeast

As summarized by the Northeast Regional Climate Center, a cool, dry November wrapped up an otherwise warm, mostly dry autumn. November was a drier-than-normal month for the Northeast, which saw 2.34 inches of precipitation or 68 percent of normal, and the Northeast's average temperature for November was 37.8 degrees F, 1.6 degrees F cooler than normal. Below-normal November precipitation was recorded in all 12 Northeast states, ranging from 49 percent of normal in Massachusetts to 85 percent of normal in Maryland. While the region saw near-normal September precipitation, October and November landed on the dry side of normal. With that, autumn was also drier than normal with 10.08 inches of precipitation, 86 percent of normal.

The USDM from October 31 showed less than one percent of the Northeast in severe drought, two percent in moderate drought, and 15 percent as abnormally dry. Below-normal precipitation, decreased streamflow and groundwater levels, and reduced soil moisture were a few factors that led to deteriorating conditions in the Northeast during November. Severe drought crept into eastern West Virginia and central Maryland, while moderate drought expanded in those states plus Pennsylvania and New York. Abnormal dryness also expanded in the Mid-Atlantic and New York and was introduced in southeastern Massachusetts. The USDM from November 28 showed less than one percent of the Northeast in severe drought, six percent in moderate drought, and 19 percent as abnormally dry. At times during November, USGS 7-day average streamflow and/or groundwater levels were below normal or lower in western and central New York, northwestern Pennsylvania, and an area from eastern West Virginia through Maryland and southern Pennsylvania into northern Delaware and southern New Jersey, with a couple of gauges reporting record low flows or levels. Water conservation was encouraged in several of these areas, with mandatory water use restrictions implemented or continuing in parts of Maryland including Emmitsburg and Myersville and Pennsylvania including in York County. The Interstate Commission on the Potomac River Basin issued a special Water Supply Outlook in early November due to ongoing dry conditions in the basin. Drought monitoring operations on the river continued upstream from Washington, D.C. through much of November. Wells ran dry for at least 100 homes, as well as some businesses and farms, in part of western New York. Some residents utilized fill stations in neighboring communities or tanker trucks that were brought in to then haul water to their homes, with a dairy farm trucking in 60,000 gallons a day for its cows. Low water levels in ponds and creeks in western New York have also affected rural firefighting operations. Dry conditions increased fire danger during West Virginia's fall fire season and contributed to multiple wildfires, including one in the New River Gorge National Park and Preserve that burned over 2,000 acres. Similar conditions were found in Virginia, which saw multiple large wildfires. Smoke from these fires produced poor air quality and smoky skies in parts of the Northeast, particularly mid-month as drought conditions generally peaked in that state.

High Plains

As discussed by the High Plains Regional Climate Center, in a similar pattern to October, warmer temperatures dominated until a late-month shot of cool air and snow on Thanksgiving weekend led to serious impacts. Outside of the heavy snowfall in some places associated with this system, the region was extremely dry in November. Outside of the Thanksgiving weekend cooldown, November was the conclusion of a very warm fall for the High Plains.

Besides the Thanksgiving weekend storm, precipitation was hard to come by this month, with only isolated areas receiving above-normal amounts. Much of the region was below 25 percent of their average, with pockets of below 5 percent present. The dryness resulted in multiple places ranking in the top 5 driest, with some recording their driest November. Bone-dry conditions have plagued much of Colorado and western Kansas this entire fall. Record wetness towards the end of spring has given way to drier conditions since then. Goodland, Kansas received only 0.66 inch (16.76 mm) of precipitation this fall to rank 4th driest. Just across the state line, no precipitation was recorded in some parts of Yuma County. Further south in Colorado, Alamosa only received trace amounts to tie for 3rd place. Precipitation also flipped drastically in the Dakotas this month. Sioux Falls, South Dakota received 3.05 inches (7.75 cm) in September and October, only to observe 0.01 inch (0.254 mm) in November to rank 4th driest. The highest amount recorded in both states was just over one inch (2.54 cm), a far cry from nearly 7 inches (17.78 cm) for parts of South Dakota in October.

The dryness this month took its toll, with a sizeable increase in drought conditions in the southern High Plains. Snowfall late in the month in eastern Kansas was too late to improve conditions in November. Overall, abnormally dry to exceptional drought (D0-D4) conditions were increased by over 6 percent. Colorado was the driest in the region and, as a result, experienced a 21 percent increase in D0-D4. Extreme drought (D3) was also reintroduced in the state for the first time since May of this year. Conditions also continued to deteriorate in Kansas, with close to 90 percent of the state in D0-D4. Soil conditions in the state are less than ideal, especially heading into the winter months.

West

As summarized by the Western Regional Climate Center, this November warm records were broken in central California and Alaska with above average temperatures also occurring in New Mexico and Arizona. No areas in the western United States experienced below-average temperatures. Most of the western United States recorded average temperatures and precipitation totals, except for Montana which experienced record dry conditions and a few sporadic locations experiencing record dryness or record precipitation totals. Alaska also received a variety of record dryness and record wetness across the state.

The month of November was marked with most of the western United States recording average or below-average precipitation totals. Montana, especially, set record and near record low precipitation totals. Helena, MT recorded only 0.02 inch of precipitation, 97% below their average monthly precipitation of 0.59 inch to have their second driest November in their 141-year record. Both Livingston, MT and Broadus, MT tied their driest November records with Livingston getting 0.06 inch (90% below 0.62 inches normal), and Broadus receiving zero inches (0.47 inch less than average). A few other notable locations that received below average precipitation totals were Dillon, MT (0.36 inch below average), Baker, OR (0.71 inch below average), and Death Valley, CA (0.1 inch below normal to tie record driest).

According to the USDM at the end of November, 28 percent of the western United States was under drought conditions. This is a 3 percent decrease from October. Drought conditions improved in the Pacific Northwest and Montana but worsened in northern New Mexico. Areas of extreme (D3) and exceptional (D4) drought were occurring in New Mexico and Arizona. Moderate (D1) to severe (D2) were occurring in Utah, Montana, Idaho, Oregon, and Washington.

Alaska summary: Temperatures were warmer than average reaching record to near record normal over most of the state. For precipitation, Alaska measured vast differences with South-central and the Southeast Inside Passage recording above average totals and the Interior and Far North receiving below average totals. For below average, Tanana (0.56 inch below average) and Northway (0.51 inch below average) both tied their driest Novembers recording zero inches.

Hawaii summary: Most of Hawaii recorded average temperatures and precipitation for the month of November. Only Kahuku on O'ahu was warmer than average by 1.0-degree Fahrenheit. Most importantly, only slight improvement has been made to Hawaii's drought conditions. Hawaii has decreased from 100 percent of the state in at least abnormally dry conditions to only 96 percent, but 94 percent of the state remains in drought conditions. Three-fourths of this total is in at least severe drought (D2) or higher. Regions of extreme drought (D3) persist for the Big Island, Maui, Moloka'i, and O'ahu. No areas are currently under exceptional drought (D4).

Additional Resources


Citing This Report

NOAA National Centers for Environmental Information, Monthly Drought Report for November 2023, published online December 2023, retrieved on July 24, 2024 from https://www.ncei.noaa.gov/access/monitoring/monthly-report/drought/202311.