Ohio frost dates: R
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Racine | Apr 28 | Oct 19 | 174 d | 6b |
| Radnor | Apr 19 | Oct 26 | 190 d | 6b |
| Randolph | Apr 21 | Oct 29 | 191 d | 6b |
| Rarden | Apr 21 | Oct 24 | 186 d | 6b |
| Ravenna | Apr 21 | Oct 29 | 191 d | 6a |
| Rawson | Apr 19 | Oct 23 | 187 d | 6a |
| Ray | Apr 22 | Oct 21 | 182 d | 6b |
| Rayland | Apr 23 | Oct 25 | 185 d | 6b |
| Raymond | Apr 19 | Oct 26 | 190 d | 6a |
| Reedsville | Apr 14 | Oct 30 | 199 d | 6b |
| Reesville | Apr 20 | Oct 20 | 183 d | 6b |
| Reno | Apr 23 | Oct 26 | 186 d | 6b |
| Republic | Apr 23 | Oct 23 | 183 d | 6a |
| Reynoldsburg | Apr 18 | Oct 27 | 192 d | 6b |
| Richfield | Apr 30 | Oct 21 | 174 d | 6b |
| Richmond | Apr 29 | Oct 20 | 174 d | 6b |
| Richmond Dale | Apr 22 | Oct 21 | 182 d | 6b |
| Richwood | Apr 25 | Oct 20 | 178 d | 6a |
| Ridgeville Corners | Apr 23 | Oct 24 | 184 d | 6a |
| Ridgeway | Apr 22 | Oct 24 | 185 d | 6a |
| Rio Grande | Apr 18 | Oct 28 | 193 d | 6b |
| Ripley | Apr 29 | Oct 11 | 165 d | 6b |
| Risingsun | Apr 22 | Oct 25 | 186 d | 6b |
| Rittman | Apr 29 | Oct 14 | 168 d | 6a |
| Robertsville | Apr 24 | Oct 26 | 185 d | 6a |
| Rock Camp | Apr 22 | Oct 23 | 184 d | 7a |
| Rock Creek | May 10 | Oct 10 | 153 d | 6a |
| Rockbridge | Apr 30 | Oct 14 | 167 d | 6b |
| Rockford | Apr 27 | Oct 19 | 175 d | 6a |
| Rocky Ridge | Apr 20 | Oct 27 | 190 d | 6b |
| Rocky River | Apr 20 | Nov 3 | 197 d | 7a |
| Rogers | May 2 | Oct 13 | 164 d | 6b |
| Rome | May 10 | Oct 10 | 153 d | 6a |
| Rootstown | Apr 21 | Oct 29 | 191 d | 6a |
| Roseville | Apr 19 | Oct 25 | 189 d | 6a |
| Rosewood | Apr 27 | Oct 20 | 176 d | 6a |
| Ross | Apr 19 | Oct 22 | 186 d | 6b |
| Rossburg | Apr 21 | Oct 20 | 182 d | 6a |
| Rossford | Apr 20 | Oct 27 | 190 d | 6b |
| Roundhead | Apr 22 | Oct 27 | 188 d | 6a |
| Rudolph | Apr 22 | Oct 25 | 186 d | 6a |
| Rushsylvania | Apr 22 | Oct 27 | 188 d | 6a |
| Rushville | Apr 22 | Oct 24 | 185 d | 6a |
| Russells Point | Apr 22 | Oct 27 | 188 d | 6a |
| Russellville | Apr 29 | Oct 11 | 165 d | 6b |
| Russia | Apr 18 | Oct 23 | 188 d | 6a |
| Rutland | Apr 27 | Oct 14 | 170 d | 6b |