Washington frost dates: R
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Rainier | Apr 29 | Oct 14 | 168 d | 8b |
| Randle | Apr 30 | Oct 8 | 161 d | 8a |
| Ravensdale | Apr 3 | Nov 11 | 222 d | 8b |
| Raymond | Apr 26 | Oct 17 | 174 d | 8a |
| Reardan | May 10 | Sep 26 | 139 d | 6b |
| Redmond | Mar 8 | Nov 23 | 260 d | 8b |
| Renton | Mar 13 | Nov 16 | 248 d | 9a |
| Republic | May 30 | Sep 10 | 103 d | 6a |
| Retsil | Mar 29 | Nov 14 | 230 d | 9a |
| Rice | May 2 | Oct 2 | 153 d | 6b |
| Richland | Apr 6 | Oct 24 | 201 d | 7b |
| Ridgefield | Apr 26 | Oct 18 | 175 d | 8b |
| Ritzville | May 7 | Oct 10 | 156 d | 6b |
| Riverside | Apr 30 | Oct 7 | 160 d | 6b |
| Rochester | Apr 22 | Oct 27 | 188 d | 8b |
| Rock Island | Apr 8 | Oct 24 | 199 d | 7a |
| Rockford | May 11 | Oct 5 | 147 d | 6b |
| Rockport | Apr 16 | Oct 25 | 192 d | 7a |
| Rollingbay | Mar 29 | Nov 14 | 230 d | 9a |
| Ronald | May 9 | Oct 6 | 150 d | 7a |
| Roosevelt | May 16 | Oct 9 | 146 d | 7a |
| Rosalia | May 7 | Sep 28 | 144 d | 6b |
| Rosburg | Apr 24 | Oct 20 | 179 d | 8b |
| Roslyn | May 13 | Sep 25 | 135 d | 7a |
| Roy | Apr 11 | Oct 30 | 202 d | 8b |
| Royal City | Apr 23 | Oct 12 | 172 d | 7a |
| Ryderwood | Apr 5 | Oct 25 | 203 d | 8b |