Average Temperatures for Illinois in October





Average temperatures for October at cities throughout Illinois are listed below.

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

The tables give the normal maximum and minimum temperatures based on weather data collected from 1991 to 2020 by the US National Centers for Environmental Information.

Chicago Area

Average October temperatures
High °F Low °F Place High °C Low °C
63 43 Aurora 17 6
63 43 Chicago Botanical Garden 17 6
64 47 Chicago Midway Airport 18 8
63 45 Chicago O'Hare Airport 17 7
63 41 Elgin 17 5
63 43 Joliet 17 6
62 40 Rochelle 17 4

Northern Illinois

Average temperatures in October
High °F Low °F Place High °C Low °C
61 42 Antioch 16 6
62 41 DeKalb 17 5
63 42 Dixon 17 6
62 39 Freeport 16 4
65 43 Moline 18 6
62 42 Rockford 17 5
61 43 Waukegan 16 6

Central Illinois

Normal temperatures for October
High °F Low °F Place High °C Low °C
68 48 Alton 20 9
63 42 Bloomington 17 6
69 46 Cahokia 21 8
66 44 Champaign 19 7
69 46 Charleston 21 8
67 44 Danville 19 7
65 46 Decatur 19 8
65 43 Kankakee 18 6
64 43 Ottawa 18 6
65 44 Peoria 19 7
65 45 Quincy 19 7
67 45 Springfield 20 7

Southern Illinois

Average October temperatures
High °F Low °F Place High °C Low °C
73 47 Belleville 23 8
71 48 Cairo 22 9
70 44 Carbondale 21 7
68 45 Mt Vernon 20 7
Reference

NOAA National Centers for Environmental Information (NCEI). Climate Normals.

Illinois Temperatures
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