Frost dates in Ottumwa, IA
The average last spring frost in Ottumwa is around April 19 and the first fall frost is around October 15. That gives Ottumwa an average growing season of about 179 days.
Last spring frost
| Early (10% chance after) | April 6 |
|---|---|
| Average (50%) | April 19 |
| Late (90%) | May 4 |
First fall frost
| Early (10%) | October 2 |
|---|---|
| Average (50%) | October 15 |
| Late (90% chance before) | October 29 |