Washington frost dates: N
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Naches | May 8 | Oct 2 | 147 d | 7a |
| Nahcotta | Apr 6 | Oct 26 | 203 d | 9a |
| Napavine | Apr 5 | Oct 25 | 203 d | 8a |
| Naselle | Apr 24 | Oct 20 | 179 d | 8b |
| Neah Bay | Apr 20 | Oct 26 | 189 d | 9a |
| Neilton | Apr 7 | Nov 10 | 217 d | 8b |
| Nespelem | Apr 22 | Oct 21 | 182 d | 6b |
| Newman Lake | Apr 26 | Oct 15 | 172 d | 6b |
| Newport | May 12 | Sep 21 | 132 d | 6a |
| Nine Mile Falls | May 10 | Sep 26 | 139 d | 6b |
| Nooksack | Apr 18 | Oct 18 | 183 d | 8a |
| Nordland | Mar 1 | Nov 28 | 272 d | 9a |
| North Bend | Apr 23 | Nov 1 | 192 d | 8a |
| North Bonneville | Mar 14 | Nov 27 | 258 d | 9a |
| North Lakewood | Apr 22 | Oct 19 | 180 d | 8a |
| Northport | May 8 | Oct 1 | 146 d | 6b |