Soil moisture continued to decline across Illinois with levels at 2 inches 27 percent lower on August 15 than those from July 15, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program Manager at the Prairie Research Institute, Illinois State Water Survey, University of Illinois.
Soil moisture in the state averaged 0.17 water fraction by volume (wfv) at depths of 2 inches on August 15, which is significantly lower than the historical average of 0.25 wfv. Levels dropped throughout the state with central Illinois having the lowest numbers, averaging 0.14 wfv or just at the wilting point for most soils measured.
Levels also declined at the deeper depths with a statewide average of 0.23 wfv at 20 inches, a 37 percent decline from July 15.
Soil temperatures have declined slightly over the past month. Temperatures at depths of 4 inches measured under bare soil averaged 77.4 degrees F statewide, 5 degrees less than on July 15. Declines were also seen at measurements made under sod with averages of 75.8 degrees and 74.6 degrees at depths of 4 and 8 inches, respectively.
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).
Maps of soil temperatures and moisture levels can also be found at the WARM website (http://www.isws.illinois.edu/warm/soiltemp.asp).