North Dakota frost dates: W
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Wahpeton | May 4 | Oct 3 | 152 d | 4a |
| Walcott | May 6 | Sep 29 | 146 d | 4a |
| Wales | May 17 | Sep 26 | 132 d | 3b |
| Walhalla | May 12 | Sep 30 | 141 d | 4a |
| Warwick | May 6 | Oct 5 | 152 d | 4a |
| Washburn | May 12 | Sep 30 | 141 d | 4a |
| Watford City | May 9 | Sep 27 | 141 d | 4a |
| Webster | May 12 | Sep 30 | 141 d | 4a |
| West Fargo | May 10 | Sep 30 | 143 d | 4a |
| Westhope | May 14 | Sep 25 | 134 d | 3b |
| Wheatland | May 9 | Oct 1 | 145 d | 4a |
| White Earth | May 11 | Sep 26 | 138 d | 4a |
| Wildrose | May 18 | Sep 20 | 125 d | 3b |
| Williston | May 21 | Sep 21 | 123 d | 4a |
| Willow City | May 21 | Sep 20 | 122 d | 3b |
| Wilton | May 11 | Sep 30 | 142 d | 4a |
| Wimbledon | May 11 | Sep 28 | 140 d | 4a |
| Wing | May 13 | Sep 29 | 139 d | 4a |
| Wishek | May 13 | Sep 27 | 137 d | 4a |
| Wolford | May 22 | Sep 20 | 121 d | 3b |
| Woodworth | May 10 | Sep 28 | 141 d | 4a |
| Wyndmere | May 6 | Sep 29 | 146 d | 4a |