Frost dates in Iron Mountain, MI
The average last spring frost in Iron Mountain is around May 26 and the first fall frost is around September 29. That gives Iron Mountain an average growing season of about 126 days.
Last spring frost
| Early (10% chance after) | May 14 |
|---|---|
| Average (50%) | May 26 |
| Late (90%) | June 3 |
First fall frost
| Early (10%) | September 15 |
|---|---|
| Average (50%) | September 29 |
| Late (90% chance before) | October 9 |