Frost dates in Mattoon, WI
The average last spring frost in Mattoon is around May 20 and the first fall frost is around September 24. That gives Mattoon an average growing season of about 127 days.
Last spring frost
| Early (10% chance after) | May 6 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 6 |
First fall frost
| Early (10%) | September 7 |
|---|---|
| Average (50%) | September 24 |
| Late (90% chance before) | October 6 |