CHAMPAIGN — State climatologist Jim Angel, who is based at the Illinois State Water Survey at the University of Illinois in
Champaign, says the average figures are 40.6 degrees and 6.7 inches.
That’s 10.7 degrees and four inches, respectively, above average. The only December with more precipitation was that of 1982, with 7.17 inches.
And, if you are saying, good thing all that rain wasn’t snow, Angel says you’ve got something there.
“There is kind of a rule of thumb,” says Angel. “It’s a 10-to-1 ratio, so one inch of rain equals ten inches of snow. Say we had eight inches of rain (in parts of southern Illinois) – that would have translated to eighty inches of snow on average.”