Frost dates in Colwell, IA
The average last spring frost in Colwell is around May 2 and the first fall frost is around October 4. That gives Colwell an average growing season of about 155 days.
Last spring frost
| Early (10% chance after) | April 17 |
|---|---|
| Average (50%) | May 2 |
| Late (90%) | May 16 |
First fall frost
| Early (10%) | September 21 |
|---|---|
| Average (50%) | October 4 |
| Late (90% chance before) | October 17 |