Monday, November 21, 2016

Chances of A White Christmas Across the Country

It's official. The first snowflakes of the season have fallen in Rockford. Nothing accumulated, but it showed signs of change from the otherwise mild and dry fall. Now that we have our first flakes under our belt, what can we look for as we head towards Christmas? That's the big question that everyone wants answered: "Will we have a White Christmas?" Answering that question accurately is nearly impossible over a month ahead of time, but what we can do is take a look at what historical averages suggest.
The map shown above depicts the historical probability of having a White Christmas using the last 30 years of data. A White Christmas is defined as having 1" of snowfall on the ground. As you can see, northern Illinois and southern Wisconsin fall in the 40-60% chance of seeing a White Christmas category.

For example, Freeport has seen 15 of the last 30 Christmas mornings feature at least 1" of snow on the ground. That is right at 50%. Most locations across northern Illinois have recorded a White Christmas 15 of the last 30 years. And, believe it or not, in 1951 Dixon had 25" of snow on the ground on Christmas. Meanwhile, Paw Paw had an incredible 27" on the ground! That year featured the most snowpack on a Christmas ever recorded across northern Illinois. The most snow to ever fall in Rockford on Christmas occurred in 1909, when the city recorded 6".

Going all the way  back to 1905, Rockford has seen 65 Christmas Day's with no snow, 21 Christmas Day's with a trace of snow, and 21 Christmas's with more than a trace of snow. Overall, we have had more days without snow than with snow.

Areas that are nearly always white on Christmas include Main, Upstate New York, Minnesota, and the mountains across the Western United States. So if you want to see the white stuff fly, head to one of those locations!

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