Frost dates in Hermantown, MN
The average last spring frost in Hermantown is around May 13 and the first fall frost is around October 10. That gives Hermantown an average growing season of about 150 days.
Last spring frost
| Early (10% chance after) | May 1 |
|---|---|
| Average (50%) | May 13 |
| Late (90%) | May 23 |
First fall frost
| Early (10%) | September 23 |
|---|---|
| Average (50%) | October 10 |
| Late (90% chance before) | October 19 |