Illinois Annual Rainfall see below for individual cities 


 

Illinois city precipitation totals

City

Avg Annual Precip

Avg Snow Annual

 Avg. days of Precip Avg # snow days Avg # thunderstorm days Avg # hail days
Chicago 36.27 38.0 126 69 38 2
Moline 38.04 30.5 114 51 46 1
Peoria 36.03 25.0 114 50 30 2
Rockford 36.63 34.5 118 70 43 2
Springfield 35.56 23.1 114 50 50 1
State Average - 39.32 inches, 37th wettest in U.S. 

Illinois Precipitation Records 

  • Driest location ranked by lowest annual average precipitation: Waukegan, northern Illinois, 32.32"
  • Wettest location ranked by highest annual average precipitation: Rosiclare, southern Illinois, 104.18" 
  • Snowiest location ranked by highest annual average snowfall: Chicago Midway Airport, northern Illinois, 42.8"
  • State precipitation record for 24 hours - Aurora, northeastern Illinois, 7/17-18/1996, 16.94"
  • State precipitation record for 1 year - New Burnside, southern Illinois, 1950, 74.58"
  • State snowfall record for 24 hours - Astoria, western Illinois, 7/17-18/1996, 16.94"
  • State snow record for 1 season - Antioch, northeastern Illinois, 1978-1979, 103.3"
  • On 01/31/1982, a major snowstorm struck Illinois. Twenty-five inches of snow was recorded at Greenville Illinois, 
located east of Saint Louis. The storm left 4000 motorists stranded for two days
  • Winter snowfall is heaviest in the Chicago area, enhanced by lake-effect snows from Lake Michigan.
  • The number of annual days in Illinois with an inch or more of precipitation averages 11 days and the number of days with an inch 
or more of snow averages 8 days
  • Flood losses in Illinois, $257 million annually since 1983, are the third highest in the nation.

Precipitation data for other U.S. states
Data source: National Data Climatic Center