CHAMPAIGN — Recent rains increased soil moisture throughout the state, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program manager at the Illinois State Water Survey, Prairie Research Institute, University of Illinois.
Illinois received 1.92 inches of rain from Aug. 11 to 14. In comparison, the state rainfall total for the first 10 days of August was 0.70 inches. Soil moisture levels had been falling at the 2-, 4- and 8-inch depths through the first part of the month, but the recent precipitation has led to significant increases in all regions of the state.
Statewide soil moisture levels at 2 inches rose an average of 47 percent from Aug. 11 to 14 to 0.34 water fraction by volume (wfv). The highest increases occurred in southern Illinois where levels increased an average of 71 percent over the four-day period.
Soil moisture also increased at 4- and 8-inch depths to Aug. 14 levels of 0.33 wfv at both depths. Levels at depths of 20 to 59 inches remained high though no significant increases occurred.
Soil temperatures have been 2–4 degrees higher than the long-term average for the first half of August. Temperatures at 2 inches under bare soil averaged 78.7 degrees on Aug. 14 with regional averages ranging from 77.1 degrees in the east to 80.8 degrees in western Illinois. At 4 inches, temperatures averaged 78.4 degrees. Under sod, temperatures were slightly cooler with a state average of 78.3 degrees at 4 inches and 77.8 degrees at 8 inches.
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 (http://www.isws.illinois.edu/warm/) and in the Illinois Water and Climate Summary (http://www.isws.illinois.edu/warm/climate.asp).