Frost dates in Swan, IA
The average last spring frost in Swan is around April 22 and the first fall frost is around October 17. That gives Swan an average growing season of about 178 days.
Last spring frost
| Early (10% chance after) | April 8 |
|---|---|
| Average (50%) | April 22 |
| Late (90%) | May 6 |
First fall frost
| Early (10%) | October 3 |
|---|---|
| Average (50%) | October 17 |
| Late (90% chance before) | October 27 |