Soilclock

Illinois 61°F soil temperature

Updated Nov 4, 2026, 7:41 AM EST

The middle reading of 8 Illinois cities, 2 inches down, on Nov 3. Pick a city for its forecast and lawn calendar.

Illinois cities today

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

City2 in4 invs normal7 daysCrabgrass windowFall seeding ends
Chicago 61°62° +12°±0° Apr 9 – Apr 22 Oct 25
Aurora 58°59° +12°+1° Apr 13 – Apr 23 Oct 20
Rockford 58°59° +12°+1° Apr 12 – Apr 22 Oct 21
Springfield 62°63° +12°+2° Mar 31 – Apr 14 Oct 26
Peoria 61°62° +12°±0° Apr 2 – Apr 16 Oct 26
Champaign 62°63° +14°+3° Apr 4 – Apr 15 Oct 25
Schaumburg 60°61° +12°±0° Apr 12 – Apr 24 Oct 24
Decatur 62°62° +13°+4° Mar 31 – Apr 14 Oct 25

When to apply pre-emergent in Illinois

Crabgrass pre-emergent goes down when 2-inch soil holds about 50°F. Across Illinois that has typically happened first in Springfield, around Mar 31, and last in Aurora, around Apr 13. 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 Illinois

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 Illinois 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