FrostCal

Frost Dates & Planting Calendars in Idaho

In Idaho, the average last spring frost ranges from April 6 in Lewiston to May 17 in Eagle, and the average first fall frost from September 23 in Rexburg to October 26 in Lewiston Orchards. Pick a city for its full frost-date summary and 42-crop planting calendar.

CityLast Spring Frost (typical)First Fall Frost (typical)Growing SeasonUSDA 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

When to Plant in Idaho