Frost dates in Walnut, IA
The average last spring frost in Walnut is around May 4 and the first fall frost is around September 30. That gives Walnut an average growing season of about 149 days.
Last spring frost
| Early (10% chance after) | April 22 |
|---|---|
| Average (50%) | May 4 |
| Late (90%) | May 23 |
First fall frost
| Early (10%) | September 16 |
|---|---|
| Average (50%) | September 30 |
| Late (90% chance before) | October 17 |