Average Annual Temperatures in Illinois





Average annual temperatures for cities throughout Illinois are listed below.

The tables give the normal maximum and minimum yearly temperatures based on weather data collected from 1981 to 2010 by the US National Climatic Data Center.

You can jump to a separate table for each region of the state: Chicago Area, Northern Illinois, Central Illinois and Southern Illinois.

Chicago Area

Average annual temperatures
High °F Low °F Place High °C Low °C
59 41 Aurora 15 5
58 40 Chicago Botanical Garden 15 5
59 44 Chicago Midway Airport 15 6
59 41 Chicago O'Hare Airport 15 5
61 45 Chicago University 16 7
59 39 Elgin 15 4
60 41 Joliet 16 5

Northern Illinois

Average temperatures for the year
High °F Low °F Place High °C Low °C
57 39 Antioch 14 4
58 39 DeKalb 14 4
58 38 Dixon 15 4
58 38 Freeport 15 3
61 41 Moline 16 5
59 39 Rockford 15 4
57 39 Waukegan 14 4

Central Illinois

Average yearly temperatures
High °F Low °F Place High °C Low °C
66 48 Alton 19 9
66 46 Cahokia 19 8
63 43 Danville 17 6
62 42 Peoria 16 6
62 43 Quincy 17 6
63 43 Springfield 17 6
62 42 Urbana 17 5

Southern Illinois

Annual average temperature
High °F Low °F Place High °C Low °C
68 47 Cairo 20 9
64 44 Marion 18 6
64 44 Mt Vernon 18 7
Reference

National Climatic Data Center. NOAA's 1981-2010 Climate Normals.

Illinois Temperatures
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