U.S. slightly cooler and wetter than normal in May

June 9, 2011

Last month, the contiguous United States had dramatic shifts in regional temperatures, but overall May was slightly cooler and wetter than normal. The spring was marked by record moisture in the Northwest and the Ohio River Valley, while drought conditions intensified across the South, according to scientists at NOAA’s National Climatic Data Center (NCDC) in Asheville, N.C.

The average U.S. temperature in May was 60 degrees F, which is 1.0 degrees F below the long-term (1901-2000) average. Precipitation was 0.34 inches above the long-term average. This monthly analysis, based on records dating back to 1895, is part of the suite of climate services NOAA provides.

May 2011 temperature "divisional rank" maps.

May 2011 temperature "divisional rank" maps are available at the NCDC site.

High resolution (Credit: NOAA)

U.S. Climate Highlights – May 

May 2011 precipitation "divisional rank" map.

May 2011 precipitation "divisional rank" map are available at the NCDC site.

High resolution (Credit: NOAA)

U.S. Climate Highlights – Spring (March-May)

U.S. Climate Highlights – Year-To-Date and Last 12 months

Special Report:  Spring Extreme Events

NCDC’s monthly reports 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 new scientific methods improve NCDC’s processing algorithms.

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