Frost dates in Mahnomen, MN
The average last spring frost in Mahnomen is around May 14 and the first fall frost is around September 21. That gives Mahnomen an average growing season of about 130 days.
Last spring frost
| Early (10% chance after) | April 12 |
|---|---|
| Average (50%) | May 14 |
| Late (90%) | June 1 |
First fall frost
| Early (10%) | September 2 |
|---|---|
| Average (50%) | September 21 |
| Late (90% chance before) | October 11 |