Frost dates in Koyukuk, AK
The average last spring frost in Koyukuk is around May 20 and the first fall frost is around September 3. That gives Koyukuk an average growing season of about 106 days.
Last spring frost
| Early (10% chance after) | May 10 |
|---|---|
| Average (50%) | May 20 |
| Late (90%) | June 3 |
First fall frost
| Early (10%) | August 20 |
|---|---|
| Average (50%) | September 3 |
| Late (90% chance before) | September 18 |