Frost dates in Zwingle, IA
The average last spring frost in Zwingle is around April 29 and the first fall frost is around October 7. That gives Zwingle an average growing season of about 161 days.
Last spring frost
| Early (10% chance after) | April 16 |
|---|---|
| Average (50%) | April 29 |
| Late (90%) | May 13 |
First fall frost
| Early (10%) | September 25 |
|---|---|
| Average (50%) | October 7 |
| Late (90% chance before) | October 22 |