As of December 21, Illinois remains 10.2 degrees below normal for the month. At 20.9 degrees, this is now the 5th coldest December since statewide records began in 1895. It could still move up or down in the ranking, depending on how the rest of December behaves.
Statewide precipitation stands at 1.06 inches of precipitation (rainfall plus the water equivalent of any snow).
Snowfall totals for the month ranges from less than 2 inches in far southern Illinois to over 14 inches in northwest Illinois (see map below). Right now the two spots with the most snowfall in the state for December are a CoCoRaHS site near Marseilles with 18.5 inches and a CoCoRaHS site near Champaign with 18.3 inches of snow.
From my web page on current conditions in Illinois, here is the breakdown by region within the state as well as the statewide numbers at the bottom for December 1-21.
Illinois 12/01/2010 to 12/21/2010 Climate <------Temperature-----> <---------Precipitation---------> Division Actual Normal Dev Actual Normal Dev Percent ----------------------------------------------------------------------------- Northwest 15.2 26.3 -11.0 1.44 1.45 -0.01 99 Northeast 17.0 27.9 -10.9 1.30 1.63 -0.33 80 West 21.4 29.7 -8.3 0.56 1.63 -1.07 34 Central 18.9 29.7 -10.8 1.13 1.76 -0.63 64 East 17.6 30.1 -12.4 1.53 1.75 -0.23 87 West-southwest 23.8 32.5 -8.6 0.56 1.91 -1.35 29 East-southeast 23.3 33.6 -10.2 1.23 2.04 -0.80 61 Southwest 26.2 35.7 -9.5 0.79 2.31 -1.52 34 Southeast 26.4 36.4 -10.0 0.93 2.43 -1.50 38 State 20.9 31.1 -10.2 1.06 1.86 -0.79 57 Dev means Deviation From Normal, Percent means Percent of Normal