Frost dates in Flagstaff, AZ
The average last spring frost in Flagstaff is around June 9 and the first fall frost is around September 24. That gives Flagstaff an average growing season of about 107 days.
Last spring frost
| Early (10% chance after) | May 21 |
|---|---|
| Average (50%) | June 9 |
| Late (90%) | June 22 |
First fall frost
| Early (10%) | September 13 |
|---|---|
| Average (50%) | September 24 |
| Late (90% chance before) | October 8 |