December 2015 Climate Summary Now Available

Overview - Warm and Wet to End 2015

Warm and wet conditions prevailed across much of the contiguous U.S. during the month of December. The warmth was very impressive, as nearly all states in the eastern half of the U.S. had their warmest Decembers on record, reporting temperatures of 9.0-15.0 degrees F (5.0-8.3 degrees C) above normal. There were reports of homeowners living as far north as Maryland that were still mowing their lawns. In the High Plains region, there were no statewide average temperature records broken for the month, but several individual stations reported a top 10 warmest December on record, especially in Kansas. December was not warm the entire month, however. The pattern shifted from warm to cold during the last week of December, bringing below normal temperatures to much of the region. Had it remained warm, temperature records would have been even more impressive.

Record-breaking precipitation was a top story for the month as well. While only two states in the contiguous U.S. had their wettest Decembers on record, the majority of states experienced above average precipitation for the month, and there were no states that had below average precipitation. One particularly interesting aspect of the wetness was that in some places that ordinarily get snow in December, the precipitation came as rain instead. In the Northeast, many locations were far behind their normal snowfall accumulation for the season. Buffalo, New York, which is noted for its abundance of lake-effect snow, had only received 1.0 inches (2.5 cm) of snow as of the end of December, which was 35.2 inches (89 cm) below normal! The lack of cold air masses moving across the Great Lakes has minimized lake-effect snow so far this season. In the High Plains region, large areas of South Dakota, Nebraska, and Kansas experienced 400-800 percent of normal precipitation. There were so many locations that had a top 10 wettest December on record, they could not all be listed in the summary. Some notable records included Salina, KS, Lincoln, NE, and Omaha, NE (wettest); Flandreau, SD (2^nd wettest); and Yankton, SD (3^rd wettest).

For more information on temperature, precipitation, and impacts from climate in December in the High Plains region, please see the link to the full PDF of the summary: http://hprcc.unl.edu/climatesummaries.php