Frost dates in Colstrip, MT
The average last spring frost in Colstrip is around May 19 and the first fall frost is around September 23. That gives Colstrip an average growing season of about 127 days.
Last spring frost
| Early (10% chance after) | April 28 |
|---|---|
| Average (50%) | May 19 |
| Late (90%) | June 4 |
First fall frost
| Early (10%) | September 10 |
|---|---|
| Average (50%) | September 23 |
| Late (90% chance before) | October 11 |