Over the term of official snow records, which date back to the 1884-85 season, a White Christmas is defined as a December 25th which has 1″ or more of snow on the ground as the day dawns.
For this year, prospects come in at 40% in the city of Chicago and as high as 50% inland away from the lake. In other words, as a historic proposition, prospects for a cover of snow on Christmas Day come in under 50-50.
We keep a watchful eye on model forecasts, which don’t yet reach with great reliability to Christmas, for signs of a snow system capable of depositing a snow accumulation for Christmas.
What can be said at this point is, if there’s such a snow system out there, it isn’t showing up yet. Importantly, that doesn’t necessarily mean such a system isn’t out there. But — at least for now — it hasn’t been identified by our numerical forecast models yet.
But the search continues!
In the meantime, here’s what history tells us about White Christmas possibilities in Chicago and across the country over the term of official records.
This map reflects the normal chance, or probability, of a White Christmas based on data from the 1981-2010 three-decade averages.
From the Illinois State Climatologist’s office: “The Christmas Day with the most snow on the ground in recorded history was 1951. Chicago at Midway Airport had 17 inches of snow on the ground that morning. Meanwhile nearby Aurora had an incredible 31 inches; the most any long-term site in Illinois has ever reported on the ground on December 25. Other places in northeastern Illinois reported significant snow that morning include Wheaton with 19 inches, and both Peotone and Waukegan with 21 inches. Other parts of northern Illinois had impressive amounts that morning as well, including Morrison and Dixon both with 25 inches and Paw Paw with 27 inches.”
Midwest White Christmas Map – Based on 1981-2010 Normals