Pennsylvania frost dates: R
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Railroad | Apr 19 | Oct 25 | 189 d | 7a |
| Ralston | May 16 | Oct 2 | 139 d | 6a |
| Ramey | May 13 | Oct 1 | 141 d | 6a |
| Ransom | Apr 23 | Oct 20 | 180 d | 7a |
| Ravine | Apr 20 | Oct 25 | 188 d | 7a |
| Reading | Apr 14 | Oct 29 | 198 d | 7a |
| Reamstown | Apr 14 | Nov 1 | 201 d | 7a |
| Rebersburg | May 5 | Oct 6 | 154 d | 6b |
| Rebuck | Apr 25 | Oct 22 | 180 d | 6b |
| Rector | May 5 | Oct 6 | 154 d | 6a |
| Red Hill | Apr 26 | Oct 17 | 174 d | 7a |
| Red Lion | Apr 26 | Oct 19 | 176 d | 7a |
| Reeders | May 1 | Oct 12 | 164 d | 6a |
| Reedsville | Apr 21 | Oct 24 | 186 d | 6b |
| Refton | Apr 19 | Oct 24 | 188 d | 7a |
| Rehrersburg | Apr 26 | Oct 19 | 176 d | 7a |
| Reinholds | Apr 26 | Oct 19 | 176 d | 7a |
| Renfrew | May 7 | Oct 14 | 160 d | 6b |
| Reno | May 2 | Oct 23 | 174 d | 6a |
| Renovo | Apr 30 | Oct 22 | 175 d | 6a |
| Republic | Apr 30 | Oct 18 | 171 d | 6b |
| Revere | Apr 29 | Oct 16 | 170 d | 6b |
| Revloc | May 17 | Oct 2 | 138 d | 6a |
| Rew | May 18 | Oct 1 | 136 d | 5b |
| Rexmont | Apr 20 | Oct 25 | 188 d | 7a |
| Reynoldsville | May 6 | Oct 14 | 161 d | 6a |
| Rheems | Apr 30 | Oct 10 | 163 d | 7a |
| Rices Landing | May 3 | Oct 15 | 165 d | 6b |
| Riceville | May 7 | Oct 10 | 156 d | 6a |
| Richboro | Apr 21 | Oct 25 | 187 d | 7a |
| Richeyville | Apr 13 | Nov 5 | 206 d | 6b |
| Richfield | Apr 25 | Oct 22 | 180 d | 6b |
| Richland | Apr 20 | Oct 25 | 188 d | 7a |
| Richlandtown | Apr 29 | Oct 16 | 170 d | 6b |
| Riddlesburg | Apr 23 | Oct 21 | 181 d | 6b |
| Ridgway | May 13 | Oct 11 | 151 d | 5b |
| Ridley Park | Apr 2 | Nov 10 | 222 d | 8a |
| Riegelsville | Apr 21 | Oct 22 | 184 d | 7a |
| Rillton | May 2 | Oct 20 | 171 d | 6b |
| Rimersburg | May 9 | Oct 11 | 155 d | 6a |
| Ringgold | May 10 | Oct 12 | 155 d | 6a |
| Ringtown | Apr 30 | Oct 22 | 175 d | 6b |
| Riverside | Apr 30 | Oct 13 | 166 d | 6b |
| Rixford | May 7 | Oct 11 | 157 d | 5b |
| Roaring Branch | May 16 | Oct 2 | 139 d | 6a |
| Roaring Spring | Apr 23 | Oct 21 | 181 d | 6b |
| Robertsdale | Apr 23 | Oct 21 | 181 d | 6b |
| Robesonia | Apr 26 | Oct 19 | 176 d | 7a |
| Robinson | May 8 | Oct 13 | 158 d | 6b |
| Rochester | Apr 27 | Oct 25 | 181 d | 6b |
| Rochester Mills | May 10 | Oct 12 | 155 d | 6a |
| Rock Glen | Apr 30 | Oct 22 | 175 d | 6b |
| Rockhill Furnace | Apr 19 | Oct 28 | 192 d | 7a |
| Rockton | May 4 | Oct 13 | 162 d | 6a |
| Rockwood | May 2 | Oct 17 | 168 d | 6a |
| Rogersville | May 3 | Oct 15 | 165 d | 6a |
| Rome | May 2 | Oct 15 | 166 d | 6a |
| Ronco | Apr 28 | Oct 21 | 176 d | 6b |
| Ronks | Apr 19 | Oct 24 | 188 d | 7a |
| Roscoe | Apr 13 | Nov 5 | 206 d | 6b |
| Rossiter | May 10 | Oct 12 | 155 d | 6a |
| Rossville | Apr 26 | Oct 19 | 176 d | 7a |
| Roulette | May 22 | Oct 1 | 132 d | 5b |
| Rouseville | May 2 | Oct 23 | 174 d | 6a |
| Rouzerville | Apr 25 | Oct 19 | 177 d | 7a |
| Rowland | May 10 | Oct 4 | 147 d | 6a |
| Roxbury | Apr 19 | Oct 24 | 188 d | 7a |
| Royersford | Apr 20 | Oct 23 | 186 d | 7a |
| Ruffs Dale | May 1 | Oct 13 | 165 d | 6b |
| Rural Ridge | Apr 16 | Nov 1 | 199 d | 6b |
| Rural Valley | May 10 | Oct 12 | 155 d | 6a |
| Rushland | Apr 13 | Oct 30 | 200 d | 7a |
| Russell | May 4 | Oct 21 | 170 d | 6a |
| Russellton | Apr 16 | Nov 1 | 199 d | 6b |