North Dakota frost dates: N
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Napoleon | May 13 | Sep 28 | 138 d | 4a |
| Neche | May 12 | Sep 30 | 141 d | 4a |
| Nekoma | May 15 | Sep 22 | 130 d | 3b |
| New England | May 16 | Sep 24 | 131 d | 4b |
| New Leipzig | May 20 | Sep 23 | 126 d | 4a |
| New Rockford | May 12 | Sep 28 | 139 d | 4a |
| New Salem | May 18 | Sep 24 | 129 d | 4a |
| New Town | May 20 | Sep 20 | 123 d | 4a |
| Newburg | May 15 | Sep 25 | 133 d | 3b |
| Niagara | May 11 | Sep 28 | 140 d | 4a |
| Nome | May 3 | Oct 5 | 155 d | 4a |
| Noonan | May 17 | Sep 23 | 129 d | 3b |
| Northwood | May 11 | Sep 28 | 140 d | 4a |
| Norwich | May 9 | Oct 1 | 145 d | 4a |