Climate Change

December 2011 was the globe's 10th warmest December on record, according to the National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC). December 2011 global land temperatures were the 8th warmest on record, and ocean temperatures were the 16th warmest on record. Global satellite-measured temperatures for the lowest 8 km of the atmosphere near average, the 15th or 12th warmest in the 34-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH). Wunderground's weather historian, Christopher C. Burt, has a comprehensive post on the December 2011 Global Weather Extremes Summary.

In the contiguous U.S., December ranked as the 34th warmest December in the 117-year record. Fifteen states in the Northeast and Upper Midwest recorded a top-ten warmest December, and one state, New Mexico, had a top-ten coldest December. Three states had a top-ten wettest December--Ohio, Arkansas, and Kansas. Seven states had a top-ten driest month--California, Nevada, Oregon, Washington, Idaho, Montana, and South Dakota. Texas had its 19th wettest December on record, helping soften extreme to exceptional drought conditions, according to the U.S. Drought Monitor.

A borderline weak/moderate La Niña event continues in the equatorial Pacific, where sea surface temperatures were approximatley 1.0°C below average during the first half of January. The impacts of a La Niña on U.S. weather are well-defined. It is likely that the drought in the South, especially Texas, will continue, along with above average temperatures. The Northwest can expect cooler and wetter conditions than average.

Arctic sea ice extent was at its third lowest on record in December, behind 2006 and 2010, according to the National Snow and Ice Data Center. Sea ice records date back to 1979.

The Iconic Image Gallery is a collection of figures that show important climactic trends. Click on a full-sized version of the image, the message that it contains, and a discussion of what makes it 'iconic'. Keep checking back we'll be posting additional images soon!