Frost dates in Superior, MT
The average last spring frost in Superior is around May 26 and the first fall frost is around September 15. That gives Superior an average growing season of about 112 days.
Last spring frost
| Early (10% chance after) | May 5 |
|---|---|
| Average (50%) | May 26 |
| Late (90%) | June 27 |
First fall frost
| Early (10%) | August 29 |
|---|---|
| Average (50%) | September 15 |
| Late (90% chance before) | October 3 |