Weather Avenue > 
Weather America > 
United States > 
Illinois > 
| Month | Max. | Min. | Avg. |
|---|---|---|---|
| January | 7°C | -24°C | -3°C |
| February | 19°C | -9°C | 5°C |
| March | 20°C | -2°C | 6°C |
| April | 26°C | 1°C | 11°C |
| May | 28°C | 8°C | 17°C |
| June | 33°C | 12°C | 22°C |
| July | 32°C | 15°C | 23°C |
| August | 35°C | 14°C | 23°C |
| September | 34°C | 10°C | 21°C |
| October | 30°C | -2°C | 14°C |
| November | 17°C | -9°C | 6°C |
| December | 12°C | -4°C | 4°C |
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