North Dakota frost dates: L
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Lakota | May 11 | Sep 28 | 140 d | 4a |
| Lamoure | May 10 | Sep 28 | 141 d | 4b |
| Langdon | May 17 | Sep 26 | 132 d | 3b |
| Lankin | May 11 | Sep 28 | 140 d | 4a |
| Lansford | May 17 | Sep 23 | 129 d | 4a |
| Larimore | May 11 | Sep 28 | 140 d | 4a |
| Lawton | May 15 | Sep 22 | 130 d | 4a |
| Leeds | May 15 | Sep 27 | 135 d | 4a |
| Lefor | May 18 | Sep 25 | 130 d | 4b |
| Lehr | May 13 | Sep 27 | 137 d | 4b |
| Leonard | May 9 | Oct 1 | 145 d | 4a |
| Lidgerwood | May 2 | Oct 6 | 157 d | 4b |
| Lignite | May 20 | Sep 19 | 122 d | 4a |
| Linton | May 12 | Sep 29 | 140 d | 4a |
| Lisbon | May 12 | Sep 27 | 138 d | 4a |
| Litchville | May 10 | Sep 28 | 141 d | 4a |
| Luverne | May 10 | Sep 24 | 137 d | 4a |