- Month of May 2010 (0.69°C/1.24°F above the 20th century average of 14.8°C/58.6°F)
- Meteorological Spring (Northern Hemisphere)/Autumn (Southern Hemisphere) (0.73°C/1.31°F above the 20th century average)
- 2010 Year-to-Date (0.68°C/1.22°F warmer than the 20th century average)
For the month of May, most of the world's land areas were warmer than average, especially eastern North America, eastern Brazil, Scandinavia, eastern Europe, equatorial and southern Africa, eastern Russia, and southern Asia. Temperatures in eastern North America, for example, were 2°C (3.6°F) to 4°C (7.2°F) above normal. On the other hand, temperatures were below average in western North America, northern Argentina, western Europe, and interior Asia.
Ocean temperatures for May were also considerably above average by 0.55°C (0.99°F). This was the second warmest May for sea surface temperatures behind 1998. These warm averages occurred despite the cooling of equatorial Pacific temperatures, signaling the end of El Niño conditions.
In the Northern Hemisphere, rapid spring melting resulted in the lowest snow cover extent since satellite observations began in 1967. Average snow cover for the month was 4.3 million square kilometers (1.7 million square miles) below the long-term average.
Images (click to enlarge): Global temperature departures from average for May 2010, March-May 2010, and January-May 2010; historical Northern Hemisphere May snow cover departures from average, all from NCDC