First 5 Months of 2010 Were Planet's Warmest Ever

(June 16) -- April showers are supposed to bring May flowers, but this year, April global record warmth brought May global record warmth.

May was the warmest on record globally, according to the National Oceanic and Atmospheric Administration, following what was the warmest April on record. January through May was the warmest first five months of a year globally, averaging 1.22 degrees Fahrenheit above normal.

May temperatures (land and sea combined) averaged 1.24 degrees above the 20th-century average of 58.6 degrees, including the warmest land surface temperature on record and the second warmest sea surface temperature on record. NOAA's monthly temperature assessments are based on data that dates back to 1880.

Residents in the western part of the United States might be surprised to learn that global temperatures were warmer than average, since late-season storms in May resulted in more precipitation than normal, along with lower-than-average temperatures. Other parts of the globe that were cooler than normal included northern Argentina, interior Asia and western Europe.

NOAA

Arctic sea ice coverage in May was 3.7 percent below the 1979-2000 average, making it the ninth smallest extent of coverage since 1979, when such data was first collected. Antarctic sea ice, on the other hand, was 7.3 percent more extensive than average, making it the fourth greatest amount of sea ice.

This year's record warmth so far puts 2010 in the same category with the two years that ended up being the warmest on record -- 2008 and 1995 -- in the sense that all three years began with an ongoing El Nino that weakened, or completely dissipated, during the spring.

NOAA typically refers to temperature anomalies (departures from average) in both national and global climate assessments because they believe that anomalies, rather than raw data, make it easier to gauge temperature trends and because they minimize potential data problems associated with the addition or subtraction of weather monitoring locations.