Frost dates in Flat Rock, IL
The average last spring frost in Flat Rock is around April 14 and the first fall frost is around October 18. That gives Flat Rock an average growing season of about 187 days.
Last spring frost
| Early (10% chance after) | April 2 |
|---|---|
| Average (50%) | April 14 |
| Late (90%) | May 1 |
First fall frost
| Early (10%) | October 1 |
|---|---|
| Average (50%) | October 18 |
| Late (90% chance before) | November 4 |