Chances of a White Christmas in Illinois

Using snow depth data from the U.S. cooperative observer network, the chances of having at least an inch of snow on the ground on December 25 were calculated for the period 1986 to 2005, the most recent 20 years (Figure 1). Compared to the very snowy 1970s and early 1980s, the last 20 years have seen less snowfall (see snowfall trend), especially in northern Illinois. Even so, the odds of a white Christmas in southern Illinois have increased somewhat between the periods 1966-85 and 1986-2005 due to some timely snows (see Table 1).

The chances of seeing a white Christmas are the smallest in southern Illinois, 10-30 percent chance. The odds are a little better across central Illinois with a 20-30 percent chance. Naturally, the best odds are in northern Illinois with a 30 to 40 percent chance.

Figure 1. Click to enlarge.

Note that percentages can vary a lot between nearby sites, depending on how individual snow events occurred. To have a guaranteed white Christmas in the Midwest, you have to travel to Minnesota, northern Wisconsin, or northern Michigan.