Illinois State Water Survey - University of Illinois at Urbana-Champaign

State Climatologist Office for Illinois

Soil Temperature Climatology for Illinois

Dr. Jim Angel, State Climatologist

Soil temperatures are important for a variety of agricultural and horticultural activities. Long-term averages have been calculated from a network of sites established in the 1990s by the Illinois State Water Survey, called the Water and Atmospheric Resource Monitoring (WARM) program.

Maps: Dates When Soil Temperature Reaches 50 and 60 Degrees

Below are the average dates when the 4-inch soil temperature reaches 50 and 60 degrees in spring and when it reached 60 and 50 degrees in fall.

Plots: 4 and 8 inch soil temperatures

These are daily averages calculated from all available data at each station for soil temperatures at 4 and 8 inches. The measurements are made under grass. Soil temperatures under other ground covers or under bare ground will vary somewhat from those shown here.

More information on soil temperatures, including current conditions can be found on the WARM site.

Table 1. Average soil temperature at 4 and 8 inches at each site.
4-Inch Depth 8-Inch Depth
Belleville Plot Plot
Bondville Plot Plot
Brownstown Plot Plot
Carbondale Plot Plot
Champaign Plot Plot
De Kalb Plot Plot
Dixon Springs Plot Plot
Fairfield Plot Plot
Freeport Plot Plot
Kilbourne Plot Plot
Monmouth Plot Plot
Olney Plot Plot
Peoria Plot Plot
Peoria Wildlife Park Plot Plot
Perry Plot Plot
Rend Lake Plot Plot
St. Charles Plot Plot
Springfield Plot Plot
Stelle Plot Plot