South Dakota frost dates: W
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Wagner | Apr 29 | Oct 9 | 163 d | 5a |
| Wakonda | May 2 | Oct 1 | 152 d | 5a |
| Wakpala | May 3 | Oct 8 | 158 d | 4b |
| Walker | May 9 | Sep 30 | 144 d | 4b |
| Wall | May 10 | Oct 1 | 144 d | 5a |
| Wallace | May 7 | Sep 28 | 144 d | 4b |
| Wanblee | May 9 | Oct 1 | 145 d | 5a |
| Warner | May 8 | Sep 29 | 144 d | 4a |
| Wasta | May 8 | Oct 3 | 148 d | 4b |
| Watauga | May 9 | Sep 30 | 144 d | 4b |
| Watertown | May 7 | Sep 30 | 146 d | 4b |
| Waubay | May 1 | Oct 12 | 164 d | 4b |
| Webster | May 4 | Oct 6 | 155 d | 4b |
| Wentworth | May 2 | Oct 5 | 156 d | 4b |
| Wessington | May 3 | Oct 3 | 153 d | 4b |
| Wessington Springs | May 2 | Oct 8 | 159 d | 5a |
| Westport | May 7 | Sep 29 | 145 d | 4b |
| White | May 6 | Oct 3 | 150 d | 4b |
| White Lake | May 3 | Oct 5 | 155 d | 5a |
| White Owl | May 16 | Sep 26 | 133 d | 4b |
| White River | May 6 | Oct 4 | 151 d | 5a |
| Whitehorse | May 10 | Sep 30 | 143 d | 4b |
| Whitewood | May 24 | Sep 25 | 124 d | 5a |
| Willow Lake | May 5 | Oct 5 | 153 d | 4b |
| Wilmot | May 5 | Oct 1 | 149 d | 4b |
| Winfred | May 6 | Oct 3 | 150 d | 4b |
| Winner | May 1 | Oct 9 | 161 d | 5a |
| Witten | May 1 | Oct 10 | 162 d | 5a |
| Wolsey | May 6 | Oct 2 | 149 d | 4b |
| Wood | May 10 | Oct 1 | 144 d | 5a |
| Woonsocket | May 9 | Sep 28 | 142 d | 5a |
| Worthing | May 2 | Oct 2 | 153 d | 5a |
| Wounded Knee | May 9 | Oct 4 | 148 d | 5a |