Frost dates in Mountain Iron, MN
The average last spring frost in Mountain Iron is around May 17 and the first fall frost is around October 1. That gives Mountain Iron an average growing season of about 137 days.
Last spring frost
| Early (10% chance after) | April 30 |
|---|---|
| Average (50%) | May 17 |
| Late (90%) | May 29 |
First fall frost
| Early (10%) | September 20 |
|---|---|
| Average (50%) | October 1 |
| Late (90% chance before) | October 17 |