Idaho Frost Dates
Idaho has strong regional contrasts, from milder western valleys to colder mountain basins and the higher interior. Frost timing can be tricky because low spots trap cold air, so gardeners often treat sheltered valleys and elevated terrain very differently when judging safe planting windows.
Look up your exact frost dates
Frost timing shifts across Idaho with elevation and distance from water. Enter your ZIP code for dates from your nearest weather station.
Idaho locations
| ZIP | Area | Hardiness zone |
|---|---|---|
| 83201 | Pocatello | 6b |
| 83203 | Fort Hall | 5b |
| 83209 | Pocatello | 6a |
| 83220 | Bennington | 5a |
| 83234 | Downey | 6b |
| 83246 | Lava Hot Springs | 6b |
| 83332 | Hagerman | 7a |
| 83338 | Jerome | 6b |
| 83353 | Sun Valley | 5b |
| 83427 | Ammon | 5b |
| 83440 | Rexburg | 5a |
| 83460 | Rexburg | 5a |
| 83536 | Kamiah | 7a |
| 83660 | Parma | 7a |
| 83705 | Boise City | 7a |
| 83827 | Elk River | 6b |
| 83837 | Kellogg | 6b |
| 83843 | Moscow | 6b |
| 83852 | Ponderay | 6b |
| 97913 | Adrian | 7a |
| 59847 | Lolo | 5b |
| 83120 | Nordic | 5a |
| 83127 | Thayne | 5b |
| 83202 | Fort Hall | 6a |
| 83204 | Pocatello | 6a |
| 83210 | Aberdeen | 5b |
| 83211 | Rockland | 6a |
| 83212 | Rockland | 6a |
| 83213 | Arco | 5a |
| 83214 | Arimo | 6b |
| 83215 | Rockford | - |
| 83217 | Bancroft | 5a |
| 83218 | Basalt | 5b |
| 83221 | Moreland | 5b |
| 83223 | Bloomington | 5a |
| 83226 | Challis | 5b |
| 83227 | Clayton | 5b |
| 83228 | Oxford | 6b |
| 83232 | Dayton | 6a |
| 83233 | St. Charles | 5a |
| 83235 | Challis | 5b |
| 83236 | Firth | 5b |
| 83237 | Franklin | 6a |
| 83238 | Montpelier | 5b |
| 83239 | Georgetown | 5b |
| 83241 | Grace | 5b |
| 83243 | Snowville | 6a |
| 83244 | Moore | 5a |
| 83245 | Inkom | 6a |
| 83250 | McCammon | 5b |
| 83251 | Mackay | 5a |
| 83252 | Malad City | 6a |
| 83253 | Leadore | 5a |
| 83254 | Montpelier | 5a |
| 83255 | Lost River | 5a |
| 83261 | Paris | 5a |
| 83262 | Rockford | 5b |
| 83263 | Preston | 6a |
| 83271 | Rockland | 6a |
| 83272 | St. Charles | 5a |
Source: NOAA 1991–2020 U.S. Climate Normals (public domain) and USDA 2023 Plant Hardiness Zone Map. Page updated Aug 4, 2026.