South Dakota frost dates: M
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Madison | May 5 | Sep 30 | 148 d | 4b |
| Manderson | May 9 | Oct 4 | 148 d | 5a |
| Mansfield | May 11 | Sep 27 | 139 d | 4b |
| Marion | Apr 30 | Oct 7 | 160 d | 5a |
| Martin | May 13 | Oct 2 | 142 d | 5a |
| Marty | Apr 27 | Oct 13 | 169 d | 5a |
| Marvin | May 14 | Sep 28 | 137 d | 4b |
| Mc Intosh | May 9 | Sep 30 | 144 d | 4b |
| Mc Laughlin | May 12 | Sep 28 | 139 d | 4b |
| Meadow | May 10 | Oct 1 | 144 d | 4b |
| Mellette | May 11 | Sep 27 | 139 d | 4a |
| Menno | May 1 | Oct 4 | 156 d | 5a |
| Midland | May 12 | Sep 28 | 139 d | 4b |
| Milbank | May 5 | Oct 2 | 150 d | 4b |
| Milesville | May 8 | Oct 2 | 147 d | 4b |
| Miller | May 3 | Oct 3 | 153 d | 4b |
| Mission | May 9 | Oct 1 | 145 d | 5a |
| Mission Hill | Apr 27 | Oct 11 | 167 d | 5a |
| Mitchell | May 2 | Oct 6 | 157 d | 5a |
| Mobridge | May 5 | Oct 4 | 152 d | 4b |
| Monroe | Apr 30 | Oct 7 | 160 d | 5a |
| Montrose | May 7 | Sep 29 | 145 d | 5a |
| Morristown | May 20 | Sep 23 | 126 d | 4b |
| Mound City | May 8 | Oct 1 | 146 d | 4b |
| Mount Vernon | Apr 27 | Oct 11 | 167 d | 5a |
| Mud Butte | May 11 | Sep 28 | 140 d | 4b |
| Murdo | May 3 | Oct 9 | 159 d | 5a |