Last year’s global temperatures are in, and the result is that 2010 is statistically tied with 2005 for the title of the warmest year since records began in 1880.
According to the US National Oceanic and Atmospheric Administration’s National Climatic Data Center (NOAA NCDC), the global temperature for both years was 0.62°C above the 20th-century average 13.9°C; 2010 came second by a thousandth of a degree. (Climatologists usually give temperatures as anomalies relative to an average, because they are easier to compare than absolute temperatures. The last month with a temperature below average was February 1985.)
2010 set new records for the warmest March, April, May, and June. Indeed, when the seasonal cycle is removed March 2010 was the third warmest month of all time (April, May, and November 2010 were also among the top 20). The ten warmest years according to NCDC are 2005/2010, 1998, 2003/2002, 2006/2009, 2007, 2004, and 2001. The 15 warmest years have all occurred since 1995; every year since 1976 has been above average. The 2000s are the warmest decade on record, followed by the 1990s and 1980s.
2010 was the Northern Hemisphere’s warmest year and the Southern Hemisphere’s sixth warmest. The former had its warmest April, May, June, July, August, and November in 2010, while the latter had its warmest February. There was particularly strong warmth in Greenland, Canada, northern Africa, and the Middle East; as well as warmer than average temperatures in southern Africa, eastern Europe, eastern Russia, and southern Asia; and cooler than average temperatures in central Russia and northern Europe. Except for the eastern Pacific, most of the oceans were warmer than average; the North Atlantic was particularly warm.