Ohio frost dates: H
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Hallsville | Apr 17 | Oct 28 | 194 d | 6b |
| Hamden | Apr 22 | Oct 21 | 182 d | 6b |
| Hamersville | Apr 11 | Oct 30 | 202 d | 6b |
| Hamilton | Apr 22 | Oct 18 | 179 d | 6b |
| Hamler | Apr 24 | Oct 21 | 180 d | 6a |
| Hammondsville | Apr 22 | Oct 28 | 189 d | 6b |
| Hannibal | Apr 26 | Oct 26 | 183 d | 6b |
| Hanoverton | May 2 | Oct 13 | 164 d | 6a |
| Harbor View | Apr 20 | Oct 27 | 190 d | 6b |
| Harpster | Apr 29 | Oct 17 | 171 d | 6a |
| Harrisburg | Apr 23 | Oct 19 | 179 d | 6b |
| Harrison | Apr 16 | Oct 28 | 195 d | 6b |
| Harrisville | Apr 21 | Oct 25 | 187 d | 6b |
| Harrod | Apr 22 | Oct 22 | 183 d | 6a |
| Hartford | May 1 | Oct 17 | 169 d | 6a |
| Hartville | Apr 24 | Oct 26 | 185 d | 6b |
| Harveysburg | Apr 18 | Oct 24 | 189 d | 6b |
| Haskins | Apr 22 | Oct 25 | 186 d | 6b |
| Haverhill | Apr 20 | Oct 22 | 185 d | 7a |
| Haviland | Apr 25 | Oct 19 | 177 d | 6a |
| Haydenville | Apr 30 | Oct 14 | 167 d | 6a |
| Hayesville | Apr 30 | Oct 15 | 168 d | 6a |
| Heath | Apr 22 | Oct 18 | 179 d | 6a |
| Hebron | Apr 22 | Oct 18 | 179 d | 6a |
| Helena | Apr 21 | Oct 24 | 186 d | 6b |
| Hicksville | Apr 28 | Oct 17 | 172 d | 6a |
| Higginsport | Apr 11 | Oct 30 | 202 d | 6b |
| Highland | Apr 24 | Oct 20 | 179 d | 6b |
| Hilliard | Apr 22 | Oct 23 | 184 d | 6b |
| Hillsboro | Apr 24 | Oct 20 | 179 d | 6b |
| Hinckley | Apr 20 | Nov 3 | 197 d | 6b |
| Hiram | May 1 | Oct 20 | 172 d | 6a |
| Hockingport | Apr 14 | Oct 30 | 199 d | 6b |
| Holgate | Apr 23 | Oct 24 | 184 d | 6a |
| Holland | Apr 22 | Oct 24 | 185 d | 6b |
| Hollansburg | Apr 24 | Oct 20 | 179 d | 6a |
| Holloway | Apr 21 | Oct 25 | 187 d | 6b |
| Holmesville | May 2 | Oct 14 | 165 d | 6a |
| Homer | Apr 27 | Oct 17 | 173 d | 6a |
| Homerville | Apr 29 | Oct 19 | 173 d | 6a |
| Homeworth | May 2 | Oct 13 | 164 d | 6a |
| Hooven | Apr 16 | Oct 28 | 195 d | 6b |
| Hopedale | Apr 21 | Oct 25 | 187 d | 6b |
| Hopewell | Apr 26 | Oct 19 | 176 d | 6a |
| Houston | Apr 18 | Oct 23 | 188 d | 6a |
| Howard | May 2 | Oct 8 | 159 d | 6a |
| Hoytville | Apr 24 | Oct 21 | 180 d | 6a |
| Hubbard | May 1 | Oct 17 | 169 d | 6a |
| Hudson | Apr 30 | Oct 21 | 174 d | 6b |
| Huntsburg | May 5 | Oct 18 | 166 d | 6a |
| Huntsville | Apr 22 | Oct 27 | 188 d | 6a |
| Huron | Apr 25 | Oct 25 | 183 d | 6b |