June 6, 2008
The March-May spring season was the 36th coolest on record for the contiguous United States, according to an analysis by NOAA’s National Climatic Data Center in Asheville, N.C. Separately, last month ended as the 34th coolest May for the contiguous United States, based on records dating back to 1895.
The average spring temperature of 51.4 degrees F was 0.5 degree F below the 20th century average. The average May temperature of 60.3 degrees F was 0.7 degree F below the 20th century mean, based on preliminary data.
U.S. Temperature Highlights
- The March-May temperatures were cooler than average from the Northwest and extending throughout the central Plains and upper Mississippi Valley. In all, 19 states had a cooler-than-average spring.
- Twenty-five states were cooler than average for May. Pennsylvania was much cooler than average and ranked eighth coolest.
- The unusually cool temperatures kept the nation’s overall temperature-related residential energy demand for May above average. Based on NOAA’s Residential Energy Demand Temperature Index, contiguous U.S. temperature-related energy demand was approximately 3.5 percent above average in May, but near average for the spring season.
- Florida, Texas, and Washington were warmer than average for May.
U.S. Precipitation Highlights
- For the spring, Missouri had its fourth wettest, Arkansas its sixth wettest, Indiana and Iowa their eighth wettest and Illinois its 10th wettest. For May, Arizona, Maryland, and Nebraska were much wetter than average, with Nebraska ranking fourth wettest and Maryland fifth wettest on record.
- California had its driest spring on record, while Nevada and Utah had their 10th and 11th driest on record. For May, two states were much drier than average — New Hampshire had its ninth driest May on record and Florida its 10th driest.
- Rainfall improved drought conditions across parts of the northern Rockies, but moderate-to-extreme drought continued throughout the Great Plains, Southeast, and Southwest. About 18 percent of the U.S. was classified in moderate-to-extreme drought at the end of May compared to 23 percent a month ago, based on the U.S. Drought Monitor.
- Several strong weather systems dumped heavy rains across parts of the central Plains, Ohio Valley, and mid-Atlantic states. In some areas, this pattern has continued for the last six months, with Missouri and Illinois having the wettest December-May on record. By the end of May, 24 percent of the contiguous U.S. was classified in moderate-to-extreme “wet spell” conditions compared to 16 percent six months ago, based on the Palmer Index.
The National Oceanic and Atmospheric Administration, an agency of the US. Commerce Department, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of our nation’s coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 70 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.