California frost dates: U
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Ukiah | Mar 19 | Nov 20 | 246 d | 9a |
| Union City | Jan 7 | Dec 22 | 349 d | 10a |
| Universal City | Jan 2 | Dec 26 | 358 d | 10a |
| Upland | Jan 4 | Dec 30 | 360 d | 10a |
| Upper Lake | Mar 5 | Nov 21 | 261 d | 9a |
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Ukiah | Mar 19 | Nov 20 | 246 d | 9a |
| Union City | Jan 7 | Dec 22 | 349 d | 10a |
| Universal City | Jan 2 | Dec 26 | 358 d | 10a |
| Upland | Jan 4 | Dec 30 | 360 d | 10a |
| Upper Lake | Mar 5 | Nov 21 | 261 d | 9a |