Cold and Snow: But How Harsh Was Winter, Really?

March 24, 2011 — -- Between the extreme cold temperatures and a set of punishing snowstorms that repeatedly brought havoc to a good chunk of the eastern United States, it was a tough winter for some.

Take Nowata, Okla., for example, where temperatures in February dropped to a record 31 degrees below zero. When December lows dipped to just 31 degrees above zero, Sarasota, Fla., broke a cold-temperature record that had stood for 82 years. And in February, an Arctic blast drove Laramie, Wyo., temperatures down to a bone-chilling minus 61 degrees.

In terms of long-term temperature trends, however, just how much did Old Man Winter's wrath hit this time? Apparently, not so much.

"The last two winters being a bit colder than normal has generated a lot of headlines. But in the longer historical perspective, they're really not very exceptional," said James Hurrell, a senior climate scientist at the National Center for Atmospheric Research in Boulder, Colo.

Hurrell has just completed a new temperature analysis that shows winter of 2010-2011 was, on average, warmer than you might think -- ranked as only the 39th-coldest winter in the U.S. since 1895.

Tell that to millions of Americans who shivered through extended periods of bitter-cold over the last few months.

"It was colder than normal," in some places, Hurrell said. "But those cold regions were balanced by some very warm regions in other parts of the country."

Areas of the southwestern U.S., for example, along with parts of Alaska recorded warmer-than-average winter temperatures, according to the National Climatic Data Center in Asheville, N.C.

A vast majority of climate scientists say that -- despite natural short-term weather events that can bring wild swings of cold and warm -- long-term climate trends continue to show a gradual warming currently taking place globally, consistent with human-caused climate change.

"We are in a warming climate," said Richard Somerville, a climate scientist and distinguished professor emeritus at the Scripps Institution of Oceanography who also has served as a lead author for the Intergovernmental Panel on Climate Change. "The long-term trend is about a third of a degree Fahrenheit increase per decade."