South Dakota frost dates: S
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Saint Charles | May 3 | Oct 10 | 160 d | 5a |
| Saint Francis | May 10 | Sep 29 | 142 d | 5a |
| Saint Lawrence | May 3 | Oct 3 | 153 d | 4b |
| Saint Onge | May 12 | Oct 2 | 143 d | 5b |
| Salem | May 7 | Sep 29 | 145 d | 5a |
| Scenic | May 10 | Oct 1 | 144 d | 5a |
| Scotland | May 1 | Oct 4 | 156 d | 5a |
| Selby | May 8 | Oct 1 | 146 d | 4b |
| Seneca | May 14 | Sep 29 | 138 d | 4b |
| Sinai | May 3 | Oct 2 | 152 d | 4b |
| Sioux Falls | Apr 26 | Oct 13 | 170 d | 5a |
| Sisseton | May 4 | Oct 3 | 152 d | 4b |
| Smithwick | May 15 | Sep 27 | 135 d | 5a |
| South Shore | May 7 | Sep 28 | 144 d | 4b |
| Spearfish | May 12 | Oct 2 | 143 d | 5b |
| Spencer | May 8 | Sep 29 | 144 d | 5a |
| Springfield | May 1 | Oct 7 | 159 d | 5a |
| Stephan | May 10 | Sep 29 | 142 d | 4b |
| Stickney | May 3 | Oct 5 | 155 d | 5a |
| Stockholm | May 5 | Oct 2 | 150 d | 4b |
| Strandburg | May 5 | Oct 2 | 150 d | 4b |
| Stratford | May 6 | Sep 29 | 146 d | 4a |
| Sturgis | May 8 | Oct 3 | 148 d | 5a |
| Summit | May 14 | Sep 28 | 137 d | 4a |