Winter of 2013 - 2014: Top-10 Coldest in Midwest; Warmest on Record in California

The winter of 2013 - 2014 will go down in the history books in the Midwest U.S. as a top-ten coldest winter on record, but ranked as the warmest winter on record in California. Temperatures averaged over December 2013 - February 2014 in the contiguous U.S. made it our 34th coolest winter since records began in 1895, said NOAA's National Climatic Data Center (NCDC) in their latest State of the Climate report. The last winter that was colder was 2009 - 2010, which ranked 15th coolest. For comparison, the winter of 2012 - 2013 was the 20th warmest, and the "non-winter" of 2011 - 2012 was the 4th warmest. Seven states had a top-ten coldest winter on record in 2013 - 2014: Wisconsin, Minnesota, Iowa, Missouri, Illinois, Indiana, and Michigan. Three states had a top-ten warmest winter on record: California, Arizona, and Alaska. The Southwest had an unusually dry winter, with California, Arizona, New Mexico, and Texas all recording top-ten dryness. For the nation as a whole, it was the 9th driest winter on record. The winter average snow cover extent for the contiguous U.S. was the 10th largest since record keeping began in 1966.


Figure 1. Perhaps the most iconic image of the U.S. winter of 2013 - 2014: Traffic gridlock in Atlanta on Tuesday afternoon, January 28, 2014 after Winter Storm Leon brought 2.6" of snow, shutting down the city. Image credit: @beercontrol/twitter.

25th most extreme U.S. winter since 1910
The U.S. winter of 2013 - 2014 had the 25th highest level of extremes observed since 1910, thanks primarily to the spatial extent of cold maximum and minimum temperatures and days with precipitation, according to NOAA's U.S. Climate Extremes Index (CEI). The index tracks the percentage area of the contiguous U.S. experiencing top-10% and bottom-10% extremes in temperature, precipitation, and drought. For the Western U.S. (California and Nevada), it was the most extreme winter on record, primarily because 84% of the region experienced top-10% dryness.


Figure 2. Historical temperature ranking for the U.S. for the winter of 2013 - 2014. Seven Midwest states had a top-ten coldest winter on record, but it was the warmest winter on record in California. Image credit: National Climatic Data Center (NCDC).


Figure 3. Historical precipitation ranking for the U.S. for the winter of 2013 - 2014. California, Arizona, New Mexico, and Texas all had top-ten driest winters on record; no states had a top-ten wettest winter. Image credit: National Climatic Data Center (NCDC).


Figure 4. Despite cool winters in 2013 - 2014 and 2009 - 2010, wintertime (December, January, February) temperatures in the contiguous U.S. have increased by about 2°F over the past 100 years. Image credit: NOAA/NCDC.


Figure 5. Palmer Drought Severity Index (PDSI) for California for the winter period December, January, and February. The winter of 2013 - 2014 had the most severe drought conditions since record keeping began in 1895. January and February 2014 also set records for most severe drought conditions ever recorded in those months. Image credit: NOAA/NCDC.

February 2013: 37th coolest February for the U.S.
February 2013 was cooler than average in the contiguous U.S, ranking as the 37th coolest February since 1895, said NOAA's National Climatic Data Center (NCDC) in their latest State of the Climate report. Illinois, Iowa, and Wisconsin each had a top-ten cold February, and Arizona, California, and Utah each had a top-ten warmest February. There were 1.75 times as many record cold daily highs (2,205) and lows (1,276), compared to record warm daily highs (945) and lows (1,043.)

Have a great weekend, everyone!

Jeff Masters