Frost dates in Harlem, MT
The average last spring frost in Harlem is around May 20 and the first fall frost is around September 16. That gives Harlem an average growing season of about 119 days.
Last spring frost
| Early (10% chance after) | May 5 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 6 |
First fall frost
| Early (10%) | September 3 |
|---|---|
| Average (50%) | September 16 |
| Late (90% chance before) | October 4 |