Iowa frost dates: F
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Fairbank | Apr 30 | Oct 9 | 162 d | 5a |
| Fairfax | Apr 27 | Oct 11 | 167 d | 5a |
| Fairfield | Apr 27 | Oct 12 | 168 d | 5b |
| Farley | Apr 28 | Oct 10 | 165 d | 5a |
| Farmersburg | Apr 28 | Oct 12 | 167 d | 5a |
| Farmington | Apr 17 | Oct 22 | 188 d | 6a |
| Farnhamville | Apr 26 | Oct 10 | 167 d | 5a |
| Farragut | Apr 20 | Oct 17 | 180 d | 5b |
| Fayette | May 4 | Oct 4 | 153 d | 5a |
| Fenton | Apr 30 | Oct 6 | 159 d | 5a |
| Ferguson | Apr 28 | Oct 7 | 162 d | 5a |
| Fertile | May 3 | Oct 1 | 151 d | 5a |
| Floris | Apr 16 | Oct 22 | 189 d | 5b |
| Floyd | Apr 30 | Oct 6 | 159 d | 5a |
| Fonda | Apr 26 | Oct 7 | 164 d | 5a |
| Fontanelle | Apr 25 | Oct 12 | 170 d | 5b |
| Forest City | Apr 30 | Oct 7 | 160 d | 5a |
| Fort Atkinson | May 3 | Oct 7 | 157 d | 5a |
| Fort Dodge | Apr 28 | Oct 8 | 163 d | 5a |
| Fort Madison | Apr 12 | Oct 25 | 196 d | 6a |
| Fostoria | May 1 | Oct 3 | 155 d | 5a |
| Fredericksburg | May 2 | Oct 5 | 156 d | 5a |
| Frederika | Apr 29 | Oct 9 | 163 d | 5a |
| Fremont | Apr 23 | Oct 14 | 174 d | 5b |
| Fruitland | Apr 24 | Oct 14 | 173 d | 5b |