Last Frost Date Idaho Falls: Frost Dates, Late Frost Risk & Growing Season

When is the last spring frost and the first autumn frost in Idaho Falls? Frost dates from 30 years of data, the risk of late frost, frost-free days and planting dates.

The frost season in Idaho Falls

Last frost (average): May 13
In 1 year out of 10 it still freezes on June 9.
First frost: September 29
Frost-free season: 131 days
Frost after 15 May: in 47 % of years

Frost days per month in Idaho Falls

January: 30.8 · -12 °C
February: 27.9 · -10 °C
March: 27.5 · -4 °C
April: 19.3 · -1 °C
May: 5.1 · 4 °C
June: 0.2 · 8 °C
July: 0 · 13 °C
August: 0 · 13 °C
September: 1.1 · 7 °C
October: 13.1 · 1 °C
November: 26.5 · -5 °C
December: 30.5 · -11 °C

No weather station nearby: plain grid values, which are often a little too cold – dates may therefore be late.
Daily minimum temperatures 2 m above ground over 30 years (1991–2020), NASA POWER; station data: Deutscher Wetterdienst (CC BY 4.0). Ground frost can form while the air at 2 m is still +2 to +3 °C.