Frost dates in Garrison, IA
The average last spring frost in Garrison is around April 29 and the first fall frost is around October 5. That gives Garrison an average growing season of about 159 days.
Last spring frost
| Early (10% chance after) | April 16 |
|---|---|
| Average (50%) | April 29 |
| Late (90%) | May 12 |
First fall frost
| Early (10%) | September 22 |
|---|---|
| Average (50%) | October 5 |
| Late (90% chance before) | October 21 |