Frost dates in Sullivan, WI
The average last spring frost in Sullivan is around May 4 and the first fall frost is around October 9. That gives Sullivan an average growing season of about 158 days.
Last spring frost
| Early (10% chance after) | April 19 |
|---|---|
| Average (50%) | May 4 |
| Late (90%) | May 17 |
First fall frost
| Early (10%) | October 1 |
|---|---|
| Average (50%) | October 9 |
| Late (90% chance before) | October 26 |