Map shows climatological chance of a White Christmas in Chicago and beyond

Wondering if your area will have a White Christmas this year?

Here’s a cool interactive map from my colleagues at the Chicago Tribune which you can use to see the climatological chance of a White Christmas based on National Weather Service observations covering the period from 1981 to 2010.

The official definition of a White Christmas is any December 25 which has recorded 1″ or more of snow on the ground at 6 a.m. in the morning. Of course, it must be noted that the shortcoming in this definition is it doesn’t include Christmases on which it’s snowed past 6 a.m. producing a snow cover of 1″ or more. Still, using 6am Dec 25th as a guide, you get a good indication of the probability of Christmas Day opening with a covering snow.

Here are some historical point probabilities of a White Christmas across the Greater Chicago area.

Note: These are not forecasts–they are based on weather records and the number of observed years in which a White Christmas has occurred.

  • Chicago O’Hare: 37%
  • Chicago Midway: 41%
  • Aurora: 43%
  • Elgin: 35%
  • Glenview: 34%
  • Romeoville: 40%
  • Park Forest: 43%
  • Morris: 34%
  • Indiana Dunes: 43%
  • Valparaiso: 43%
  • Kenosha, WI: 37%

Also included are White Christmas chances for the state of Illinois from our state climatologist Dr. Jim Angel. Jim points out that, in general, the climatological chance of a White Christmas runs in the 40 to 60% range in northern Illinois; 20-40% across central Illinois and 0 to 20% across southern Illinois.

Jim also reports the most snow on the ground at Chicago Midway Airport on Christmas morning as 17″ in 1951. That same year saw an extraordinary 31″ on the ground in Aurora; 19″ Wheaton and 21″ at Peotone and Waukegan.