Frost dates in Harlowton, MT
The average last spring frost in Harlowton is around May 27 and the first fall frost is around September 14. That gives Harlowton an average growing season of about 110 days.
Last spring frost
| Early (10% chance after) | May 14 |
|---|---|
| Average (50%) | May 27 |
| Late (90%) | June 15 |
First fall frost
| Early (10%) | September 1 |
|---|---|
| Average (50%) | September 14 |
| Late (90% chance before) | September 29 |