Kentucky frost dates: O
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Oak Grove | Apr 6 | Oct 28 | 205 d | 7a |
| Oakland | Apr 12 | Oct 29 | 200 d | 7a |
| Oil Springs | Apr 19 | Oct 25 | 189 d | 7a |
| Olaton | Apr 17 | Oct 23 | 189 d | 7a |
| Olive Hill | Apr 24 | Oct 18 | 177 d | 6b |
| Olmstead | Apr 9 | Oct 28 | 202 d | 7a |
| Olympia | Apr 17 | Oct 25 | 191 d | 6b |
| Oneida | Apr 16 | Oct 26 | 193 d | 7a |
| Orlando | Apr 18 | Oct 24 | 189 d | 7a |
| Owensboro | Apr 2 | Nov 1 | 213 d | 7a |
| Owenton | Apr 11 | Oct 29 | 201 d | 6b |
| Owingsville | Apr 24 | Oct 18 | 177 d | 6b |