Skip to content

Frost dates for Idaho Falls, Idaho

In a typical year, Idaho Falls’s last spring frost lands around May 9 and the first fall frost around Oct 1, a growing season of about 145 days. These are odds drawn from 30-year NOAA climate normals, not a promise. USDA zone 5b.

Last spring frost and first fall frost odds for Idaho Falls, Idaho
OddsLast spring frostFirst fall frost
10 percentApr 27Sep 17
50 percentMay 9Oct 1
90 percentJun 2Oct 15

A 10 percent year is an early year, a 90 percent year a late one. Frost-sensitive planting usually waits for the 90 percent side of the last-frost band.

Soil in Idaho Falls is typically around 71°F at 4 inches this time of year, estimated from the last two weeks of normal air temperatures.

Plantable now in Idaho Falls

Timing comes from the same temperature engine the app uses, run against Idaho Falls’s normals for today.

See the full what-to-plant lookup

Nearby cities

Row & Bed is a plant reference built around your garden: your zone, your frost dates, your forecast, and a cited page for every variety in your beds.

Set up your garden