Frost Dates & Planting Calendars in Idaho
Typical last spring frost, first fall frost, and growing-season length for 24 cities in Idaho, based on NOAA 1991–2020 climate normals. Click a city for its full frost-date summary, monthly temperature chart, and 42-crop planting calendar.
| City | Last Spring Frost (typical) | First Fall Frost (typical) | Growing Season | USDA Zone |
|---|---|---|---|---|
| Boise | April 24 | October 21 | 179 days | 7a |
| Meridian | April 24 | October 21 | 179 days | 7a |
| Nampa | April 29 | October 13 | 164 days | 7a |
| Idaho Falls | May 9 | October 1 | 142 days | 5b |
| Pocatello | May 2 | October 11 | 161 days | 6b |
| Caldwell | April 23 | October 18 | 178 days | 7a |
| Coeur d'Alene | April 22 | October 18 | 179 days | 6b |
| Twin Falls | April 30 | October 9 | 161 days | 6b |
| Lewiston | April 6 | October 26 | 200 days | 7b |
| Lewiston Orchards | April 6 | October 26 | 200 days | 7b |
| Post Falls | April 22 | October 18 | 179 days | 6b |
| Rexburg | May 15 | September 23 | 129 days | 5a |
| Moscow | Frost-free | Frost-free | Year-round | 6b |
| Eagle | May 17 | October 12 | 147 days | 7a |
| Conda | Frost-free | Frost-free | Year-round | 5a |
| Kuna | April 24 | October 21 | 179 days | 7a |
| Ammon | May 9 | October 1 | 142 days | 5b |
| Chubbuck | May 2 | October 11 | 161 days | 6b |
| Hayden | April 22 | October 18 | 179 days | 6b |
| Mountain Home | May 2 | October 8 | 157 days | 6b |
| Blackfoot | May 5 | October 3 | 149 days | 5b |
| Garden City | April 24 | October 21 | 179 days | 7a |
| Jerome | May 2 | October 14 | 166 days | 6b |
| Burley | May 7 | October 4 | 150 days | 6b |