South Dakota frost dates: L
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Labolt | May 5 | Oct 2 | 150 d | 4b |
| Lake Andes | Apr 30 | Oct 13 | 166 d | 5a |
| Lake City | May 2 | Oct 9 | 160 d | 4a |
| Lake Norden | May 6 | Oct 1 | 148 d | 4b |
| Lake Preston | May 5 | Oct 4 | 152 d | 4b |
| Lane | May 2 | Oct 8 | 159 d | 5a |
| Langford | May 13 | Sep 26 | 136 d | 4a |
| Lantry | May 8 | Oct 1 | 146 d | 4b |
| Lead | May 18 | Sep 29 | 134 d | 5a |
| Lebanon | May 7 | Oct 2 | 148 d | 4b |
| Lemmon | May 10 | Sep 30 | 143 d | 4b |
| Lennox | May 2 | Oct 2 | 153 d | 5a |
| Leola | May 9 | Sep 28 | 142 d | 4b |
| Lesterville | May 1 | Oct 4 | 156 d | 5a |
| Letcher | Apr 27 | Oct 11 | 167 d | 5a |
| Little Eagle | May 12 | Sep 28 | 139 d | 4a |
| Lodgepole | May 30 | Sep 11 | 104 d | 4b |
| Long Lake | May 10 | Sep 30 | 143 d | 4b |
| Long Valley | May 9 | Oct 1 | 145 d | 5a |
| Lower Brule | May 6 | Oct 5 | 152 d | 4b |
| Ludlow | May 16 | Sep 26 | 133 d | 4b |
| Lyons | Apr 26 | Oct 13 | 170 d | 5a |