Frost dates in River Forest, IL
The average last spring frost in River Forest is around April 22 and the first fall frost is around October 15. That gives River Forest an average growing season of about 176 days.
Last spring frost
| Early (10% chance after) | April 9 |
|---|---|
| Average (50%) | April 22 |
| Late (90%) | May 10 |
First fall frost
| Early (10%) | October 2 |
|---|---|
| Average (50%) | October 15 |
| Late (90% chance before) | November 6 |