Average Precipitation for Illinois in October





The tables below give monthly averages for rainfall plus snowfall during October at cities in Illinois.

Each place has a total for the amount of precipitation it usually receives this month. There is also a count of the number of days with wet weather, when precipitation amounts to 0.01 inches (0.25 millimetres) or more.

The precipitation totals are averages based on weather data collected from 1991 to 2020 for the US National Centers for Environmental Information.

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 monthly precipitation in October
Days Place Inches Milli­metres
9 Aurora 3.7 94
11 Chicago Botanical Garden 3.6 91
11 Chicago Midway Airport 3.9 98
11 Chicago O'Hare Airport 3.4 87
11 Elgin 3.3 84
10 Joliet 3.1 80
9 Rochelle 2.8 71

Northern Illinois

October averages for total rainfall plus snowfall
Days Place Inches Milli­metres
10 DeKalb 3.0 75
7 Dixon 3.0 75
9 Freeport 3.0 76
9 Moline 2.8 71
10 Rockford 2.6 67
12 Waukegan 3.3 83

Central Illinois

Average amount of rain and snow in October
Days Place Inches Milli­metres
8 Alton 2.9 74
9 Bloomington 3.1 78
8 Cahokia 3.0 77
10 Champaign 3.4 85
10 Charleston 3.9 100
10 Danville 3.7 93
10 Decatur 3.4 87
9 Kankakee 3.4 86
9 Ottawa 3.1 79
10 Peoria 3.2 81
9 Quincy 3.1 77
9 Springfield 3.3 83

Southern Illinois

Precipitation totals for October
Days Place Inches Milli­metres
8 Belleville 3.1 79
9 Carbondale 3.7 94
9 Mt Vernon 3.5 90
Reference

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

Illinois Precipitation
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