Frost dates in St. Ignatius, MT
The average last spring frost in St. Ignatius is around May 23 and the first fall frost is around September 19. That gives St. Ignatius an average growing season of about 119 days.
Last spring frost
| Early (10% chance after) | May 5 |
|---|---|
| Average (50%) | May 23 |
| Late (90%) | June 11 |
First fall frost
| Early (10%) | September 6 |
|---|---|
| Average (50%) | September 19 |
| Late (90% chance before) | October 10 |