NOAA: U.S. Temperature Warmer than Average for May
June 10, 2009
The May 2009 temperature for the contiguous United States was above the long-term average, based on records going back to 1895, according to an analysis by NOAA’s National Climatic Data Center in Asheville, N.C.
The average May temperature of 62.5 degrees F was 1.4 degrees F above the 20th Century average. Precipitation across the contiguous United States in May averaged 3.22 inches, which is 0.35 inch above the 1901-2000 average.
U.S. Temperature Highlights
- California, New Mexico, and Utah respectively had their fourth, sixth, and ninth warmest May while Nevada and Arizona registered their fifth warmest May on record. Only North Dakota, Oklahoma, and Arkansas had an average monthly temperature that was below normal.
- For the January – May period, only North Dakota has experienced cooler-than-normal average temperatures. By contrast, much of the South, Southwest, and West regions have been above-normal for the period.
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand was 1.0 percent below average in May.
U.S. Precipitation Highlights
- For the contiguous United States, precipitation was above normal. Florida, 9.86 inches and Arkansas, 10.91 inches experienced their all-time wettest May.
- Several other states had much-above-normal precipitation amounts, including: Virginia, Tennessee, and Alabama (each fifth wettest), Mississippi and Nevada (each eighth wettest). West Virginia and North Carolina experienced their ninth and 10th, respectively, wettest May on record.
- By the end of May, moderate-to-exceptional drought covered 14 percent of the contiguous United States, based on the U.S. Drought Monitor.
- About 20 percent of the contiguous United States had moderately-to-extremely wet conditions at the end of May, according to the Palmer Index (a well-known index that measures both drought intensity and wet spell intensity).
- The Red River at Fargo, N.D., set records for consecutive days above flood (62 days), moderate flood (37 days), and major flood (31 days) stage. Grand Forks, N.D., also set a record with 32 straight days above moderate flood stage. Along the Illinois River, Peoria broke the record for days above flood stage with 86 days at the end of May.
- Last month, 9,265 new wildfires ignited and burned approximately 312,599 acres. The number of fires ranked May 2009 second during the past decade for number of fires, and third for acreage burned. For the year to date, 41,328 fires have burned approximately 1,377,310 acres throughout America, making 2009 the worst year -- so far -- in the past decade for number of fires, and third highest year to date for acreage burned.
NCDC’s preliminary reports, which assess the current state of the climate, are released soon after the end of each month. These analyses are based on preliminary data, which are subject to revision. Additional quality control is applied to the data when late reports are received several weeks after the end of the month and as increased scientific methods improve NCDC’s processing algorithms.
NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.