Montana frost dates: P
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Pablo | May 10 | Oct 5 | 148 d | 6a |
| Paradise | May 17 | Sep 23 | 129 d | 6a |
| Park City | May 29 | Sep 15 | 109 d | 5a |
| Peerless | May 28 | Sep 6 | 101 d | 3b |
| Pendroy | Jun 9 | Sep 3 | 86 d | 4b |
| Philipsburg | frost any month | 5a | ||
| Pinesdale | May 21 | Sep 22 | 124 d | 5b |
| Plains | frost any month | 6a | ||
| Plentywood | May 25 | Sep 14 | 112 d | 3b |
| Plevna | May 21 | Sep 20 | 122 d | 4a |
| Polaris | frost any month | 5a | ||
| Polebridge | frost any month | 5a | ||
| Polson | May 10 | Oct 5 | 148 d | 6a |
| Pompeys Pillar | May 22 | Sep 22 | 123 d | 4b |
| Pony | Apr 30 | Oct 10 | 163 d | 5a |
| Poplar | May 24 | Sep 14 | 113 d | 4a |
| Powderville | May 13 | Sep 25 | 135 d | 4b |
| Power | May 13 | Sep 27 | 137 d | 4b |
| Pray | May 19 | Sep 25 | 129 d | 5a |
| Proctor | May 1 | Oct 15 | 167 d | 6a |
| Pryor | May 14 | Sep 24 | 133 d | 5a |