Wisconsin frost dates: U
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Union Center | May 5 | Oct 4 | 152 d | 4b |
| Union Grove | May 5 | Oct 8 | 156 d | 5b |
| Unity | May 13 | Sep 26 | 136 d | 4b |
| Upson | May 23 | Oct 1 | 131 d | 4a |
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Union Center | May 5 | Oct 4 | 152 d | 4b |
| Union Grove | May 5 | Oct 8 | 156 d | 5b |
| Unity | May 13 | Sep 26 | 136 d | 4b |
| Upson | May 23 | Oct 1 | 131 d | 4a |