Average Precipitation for Illinois in May
The tables below give monthly averages for rainfall plus snowfall during May 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
Days | Place | Inches | Millimetres |
---|---|---|---|
13 | Aurora | 4.9 | 123 |
13 | Chicago Botanical Garden | 4.8 | 123 |
12 | Chicago Midway Airport | 4.8 | 121 |
13 | Chicago O'Hare Airport | 4.5 | 114 |
13 | Elgin | 5.1 | 130 |
12 | Joliet | 4.5 | 115 |
13 | Rochelle | 4.7 | 119 |
Northern Illinois
Days | Place | Inches | Millimetres |
---|---|---|---|
13 | DeKalb | 4.8 | 122 |
11 | Dixon | 4.8 | 122 |
13 | Freeport | 4.4 | 111 |
12 | Moline | 4.7 | 119 |
13 | Rockford | 4.2 | 106 |
14 | Waukegan | 3.9 | 100 |
Central Illinois
Days | Place | Inches | Millimetres |
---|---|---|---|
11 | Alton | 5.5 | 139 |
11 | Bloomington | 4.5 | 114 |
12 | Cahokia | 4.8 | 122 |
13 | Champaign | 4.8 | 121 |
13 | Charleston | 4.5 | 115 |
13 | Danville | 4.6 | 118 |
13 | Decatur | 5.0 | 126 |
12 | Kankakee | 5.2 | 131 |
12 | Ottawa | 4.5 | 114 |
13 | Peoria | 4.7 | 119 |
13 | Quincy | 4.6 | 116 |
13 | Springfield | 4.5 | 115 |
Southern Illinois
Days | Place | Inches | Millimetres |
---|---|---|---|
12 | Belleville | 5.1 | 128 |
13 | Carbondale | 5.2 | 132 |
13 | Mt Vernon | 5.1 | 129 |
Reference
NOAA National Centers for Environmental Information (NCEI). Climate Normals.