Oklahoma frost dates: N
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Nardin | Apr 12 | Oct 29 | 200 d | 7a |
| Nash | Apr 5 | Nov 1 | 210 d | 7a |
| Nashoba | Apr 11 | Oct 27 | 199 d | 7b |
| Newalla | Mar 30 | Nov 5 | 220 d | 7b |
| Newcastle | Mar 31 | Nov 5 | 219 d | 7b |
| Newkirk | Apr 10 | Oct 27 | 200 d | 7a |
| Nicoma Park | Apr 2 | Nov 5 | 217 d | 7b |
| Ninnekah | Apr 6 | Nov 1 | 209 d | 7b |
| Noble | Apr 3 | Nov 3 | 214 d | 7b |
| Norman | Apr 3 | Nov 3 | 214 d | 7b |
| North Miami | Apr 6 | Oct 27 | 204 d | 7a |
| Nowata | Apr 4 | Nov 1 | 211 d | 7a |