After such nice weather in October and most of November, real winter weather arrived in Illinois for December. The statewide average temperature for the first 14 days of December was 22.0 degrees, 10.6 degrees below normal.
The statewide average precipitation is 0.83 inches, 0.5 inches below normal.
Snowfall has been widespread across the state in early December. Snowfall totals range from less than an inch in far southern Illinois to over 10 inches in northwestern Illinois. See map below for snowfall totals for December 1-14, 2010.
Snow Climatology and Extremes for Illinois
The National Climatic Data Center has a web page that generates the snowfall climatology and extremes for any U.S. state except Hawaii (sorry).
Link: http://www.ncdc.noaa.gov/ussc/USSCAppController?action=map
From there you can pick a state and look at state-wide numbers like who had the greatest 1-day snowfall (24 inches at Coatsburg IL on Feb. 28, 1900) or the great snow depth (39 inches at Antioch on Jan. 16, 1979). You can also pull up more detailed station by station analysis of snowfall including averages and dates of the earliest and latest snowfall, etc.
Warm November in Illinois
November
The statewide average temperature for November 2010 was 43.4 degrees, which was 1.6 degrees above normal. That makes it the 26th warmest November since statewide records began in 1895.
By the way, the 2000’s are well represented in the list of warm Novembers. Their rank and year include: #1 (2001), #5 (2009), #10 (2004), #14 (2003), #16 (2005), and #17 (2006).
The statewide average precipitation for November was 3.2 inches, only 0.1 inches below normal. November was exceptionally dry until the long Thanksgiving weekend arrived. Rains from that period signaled the recovery of soil moisture around the state. See the earlier posts on this subject.
The highest monthly total precipitation in Illinois for November was 7.15 inches recorded at Mt Carmel. The highest daily temperature for November was 82 degrees recorded at Cairo on November 13. The lowest daily temperature for November was 12 degrees recorded at Mt Carroll on November 26.
Fall
The statewide average temperature for fall (September-November) was 55.4 degrees, 1.2 degrees above normal.
The statewide average precipitation for fall was 8.6 inches, 0.8 inches below normal. Widespread rains in early September and late November masked the long period in between with dry conditions.
Note: these numbers are preliminary and subject to change as more data arrives.