Soil temperatures increased through the first half of March, according to Jennie Atkins, Water and Atmospheric Resources Monitoring Program manager at the Illinois State Water Survey at the Prairie Research Institute at the University of Illinois.
Illinois saw warmer-than-average soil temperatures across the state, with temperatures 10 or more degrees above the long-term average on March 15. Temperatures at 4 inches under bare soil averaged 56.7 degrees F on March 15, 10.9 degrees higher than last year and 15.9 degrees higher than average.
Soils were warm across the state, with regional averages of 51.0 degrees in northern Illinois, 56.2 degrees in the central portion of the state, and 60.6 degrees in the south. Temperatures were warmer at depths of 2 inches, with a statewide average of 57.0 degrees.
Temperatures were slightly cooler but still warmer than normal under sod. Statewide temperatures averaged 54.5 degrees at depths of 4 inches and 52.7 degrees at 8 inches.
Soil moisture was high in mid-March, with levels near or above field capacity in most areas across the state. Moisture had been declining at depths from 2 to 20 inches in the few days prior to the March 18 report as soils dried out from the rain earlier that week. Moisture levels at depths of 39 and 59 inches remained high.
The Illinois State Water Survey’s WARM Program collects hourly and daily weather and soil information at 19 stations across the state. Daily and monthly summaries can be found at the WARM website and in the Illinois Water and Climate Summary.