Frost dates in St. Olaf, IA
The average last spring frost in St. Olaf is around May 11 and the first fall frost is around September 28. That gives St. Olaf an average growing season of about 140 days.
Last spring frost
| Early (10% chance after) | April 22 |
|---|---|
| Average (50%) | May 11 |
| Late (90%) | May 26 |
First fall frost
| Early (10%) | September 13 |
|---|---|
| Average (50%) | September 28 |
| Late (90% chance before) | October 12 |