Frost dates in Rock Falls, IA
The average last spring frost in Rock Falls is around May 6 and the first fall frost is around October 2. That gives Rock Falls an average growing season of about 149 days.
Last spring frost
| Early (10% chance after) | April 22 |
|---|---|
| Average (50%) | May 6 |
| Late (90%) | May 20 |
First fall frost
| Early (10%) | September 20 |
|---|---|
| Average (50%) | October 2 |
| Late (90% chance before) | October 17 |