Idaho frost dates: W
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Wallace | May 5 | Oct 2 | 150 d | 6b |
| Warren | frost any month | 5a | ||
| Wayan | frost any month | 5b | ||
| Weippe | Jun 3 | Sep 7 | 96 d | 6b |
| Weiser | Apr 23 | Oct 13 | 173 d | 7a |
| Wendell | May 2 | Oct 14 | 165 d | 6b |
| Weston | May 16 | Sep 28 | 135 d | 6a |
| White Bird | May 9 | Oct 3 | 147 d | 7a |
| Wilder | Apr 24 | Oct 9 | 168 d | 7a |
| Winchester | May 23 | Sep 25 | 125 d | 6b |
| Worley | May 11 | Oct 5 | 147 d | 6b |