Soilclock

Idaho 47°F soil temperature

Updated Nov 4, 2026, 7:41 AM EST

The middle reading of 2 Idaho cities, 2 inches down, on Nov 3. Pick a city for its forecast and lawn calendar.

Idaho cities today

Estimated daily average soil temperature at 2 inches, the difference from normal for the date, and the change over the last week. Idaho spans cool-season grass country.

City2 in4 invs normal7 daysCrabgrass windowFall seeding ends
Boise City 47°50° ±0°−4° Apr 5 – Apr 29 Oct 20
Idaho Falls 43°45° +2°−1° May 1 – May 18 Oct 8

When to apply pre-emergent in Idaho

Crabgrass pre-emergent goes down when 2-inch soil holds about 50°F. Across Idaho that has typically happened first in Boise City, around Apr 5, and last in Idaho Falls, around May 1. The window closes when soil holds 55°F and crabgrass starts sprouting.

Close view of a Kentucky bluegrass lawn
Kentucky bluegrass, the most common cool-season lawn grass in the northern US.

Last good week to seed in Idaho

Tall fescue and bluegrass seed sprouts best while 4-inch soil is between 55 and 70°F. The typical last day above 55°F:

What grows in Idaho lawns

Crabgrass is the weed spring pre-emergents are timed for. Lawns here are mostly cool-season grasses such as bluegrass and fescue.

Large crabgrass with its spreading finger-like seed heads
Large crabgrass in seed. Each plant can drop thousands of seeds that wait for warm spring soil.
Close view of a Kentucky bluegrass lawn
Kentucky bluegrass, the most common cool-season lawn grass in the northern US.
A low mat of bermudagrass with fine blades and seed heads
Bermudagrass, the warm-season grass behind most lawns from the Carolinas to Texas.

Other states