Washington frost dates: K
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Kahlotus | Apr 25 | Oct 15 | 173 d | 7a |
| Kalama | Apr 8 | Nov 5 | 211 d | 8b |
| Kapowsin | Apr 11 | Oct 30 | 202 d | 8b |
| Keller | Apr 22 | Oct 21 | 182 d | 7a |
| Kelso | Apr 8 | Nov 5 | 211 d | 8b |
| Kenmore | Mar 8 | Nov 23 | 260 d | 9a |
| Kennewick | Mar 28 | Oct 30 | 216 d | 7b |
| Kent | Mar 20 | Nov 10 | 235 d | 8b |
| Kettle Falls | May 2 | Oct 2 | 153 d | 6b |
| Keyport | Mar 29 | Nov 14 | 230 d | 9a |
| Kingston | Mar 9 | Nov 17 | 253 d | 9a |
| Kirkland | Mar 8 | Nov 23 | 260 d | 9a |
| Kittitas | May 8 | Oct 2 | 147 d | 6b |
| Klickitat | May 12 | Oct 11 | 152 d | 7b |