Utah frost dates: F
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Fairview | May 26 | Sep 25 | 122 d | 5b |
| Farmington | Apr 19 | Oct 19 | 183 d | 7b |
| Fayette | May 31 | Sep 21 | 113 d | 6b |
| Ferron | May 6 | Oct 10 | 157 d | 6b |
| Fielding | May 3 | Oct 12 | 162 d | 6a |
| Fillmore | May 4 | Oct 14 | 163 d | 6a |
| Fort Duchesne | May 19 | Oct 2 | 136 d | 5b |
| Fountain Green | May 26 | Sep 25 | 122 d | 5b |
| Fruitland | May 6 | Oct 5 | 152 d | 6a |