THE first nine months of 2010 tied with the same period in 1998 for the warmest combined land and ocean surface temperature on record.
The global average land surface temperature for January-September was the second warmest on record, behind 2007. The global ocean surface temperature for January–September was also the second warmest on record, behind 1998.
The monthly analysis from NOAA’s National Climatic Data Center, which is based on records going back to 1880, is part of the suite of climate services NOAA provides government, business and community leaders, so they can make informed decisions.
For the year-to-date, the global combined land and ocean surface temperature of 14.75 C tied with 1998 as the warmest January-September period on record. This value is 0.65 C above the 20th century average.
The combined global land and ocean average surface temperature for September 2010 tied with 1998 as the eighth warmest on record at 15.5 C, which is 0.50 C above the 20th century average of 15.0 C.
Separately, the September global land surface temperature was 0.66 C above the 20th century average of 12.0 C — the ninth warmest September on record. Warmer-than-average conditions dominated the world’s land areas. The most prominent warmth was in western Alaska, most of the contiguous United States, eastern Canada, Greenland, the Middle East, eastern and central Europe, western and far eastern Russia and northeastern Asia. Cooler-than-average regions included much of Australia, western Canada, parts of the northern United States, parts of western and central Europe, and central Russia.
According to NOAA’s National Weather Service, Los Angeles set a new all-time maximum temperature on Sept. 27 when temperatures soared to 113 F (45 C), surpassing the previous record of 112 F (44.4 C) set in June 1990.
According to Australia’s Bureau of Meteorology, the country had its coolest maximum temperatures since 1984. The Northern Territory had its coolest September since 1984, and Western Australia and Victoria each recorded their lowest maximum temperatures since 1992. South Australia had its second-lowest maximum temperatures on record for September. Overall, though, the nation had overnight minimum temperatures that were 1.62 F (0.90 C) above average.
The worldwide ocean surface temperature was 0.44 C above the 20th century average of 16.2 C and the ninth warmest September on record. The warmth was most pronounced in the Atlantic Ocean and the western Pacific Ocean.
La Niña’s magnitude strengthened to moderate in September, as sea surface temperatures continued to drop across the central and eastern equatorial Pacific Ocean. La Niña episodes are typically associated with global temperatures that are cooler than recent trends, and this was the case for September 2010. According to NOAA’s Climate Prediction Center, La Niña is expected to strengthen and last at least into the Northern Hemisphere spring of 2011.
Arctic sea ice reached its annual minimum on Sept. 19, according to the National Snow and Ice Data Center. The average extent of 1.89 million square miles (4.90 million square kilometers) was the third lowest September sea ice extent on record (30.4 percent below average). The annual record was set in 2007 (38.9 percent below average). This year also marked the 14th consecutive September with below-average Arctic sea ice extent.
Antarctic sea ice reached its annual maximum in September. September 2010 was the third largest sea ice extent on record (2.3 percent above average), behind 2006 (largest) and 2007 (second largest).
According to Australia’s Bureau of Meteorology, the continent received an average precipitation of 1.91 inches (48.4 millimeters) during September — this is nearly double the 1961–1990 average and the highest September value on record.
Scientists, researchers and leaders in government and industry use NOAA’s monthly reports to help track trends and other changes in the world's climate. This climate service has a wide range of practical uses, from helping farmers know what and when to plant, to guiding resource managers with critical decisions about water, energy and other vital assets.