Frost dates in Birnamwood, WI
The average last spring frost in Birnamwood is around May 17 and the first fall frost is around October 1. That gives Birnamwood an average growing season of about 137 days.
Last spring frost
| Early (10% chance after) | May 2 |
|---|---|
| Average (50%) | May 17 |
| Late (90%) | May 27 |
First fall frost
| Early (10%) | September 15 |
|---|---|
| Average (50%) | October 1 |
| Late (90% chance before) | October 16 |