CHAMPAIGN, Ill. – Soil temperatures were slightly above the long-term average in the middle of April, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program Manager at the Illinois State Water Survey, Prairie Research Institute, University of Illinois.
On April 14, soils averaged 2 to 3 degrees above the long-term average with statewide averages ranging from 56.5 degrees F for measurements at 2 inches under bare soil to 53.8 degrees at 8 inches under sod. Southern Illinois had the highest temperatures with a regional average of 57.7 degrees F, although regional averages varied by only 3 degrees across the state.
Statewide soil moisture levels have remained steady through the first half of April with an average moisture level of 0.34 water fraction by volume (wfv) at 2 inches on April 14. Slightly wetter conditions were seen at 39 and 59 inches, with averages of 0.43 wfv at both depths.
Differences were observed between the regions. The wettest soils were in southern Illinois with an average level of 0.43 wfv at 2 inches on April 14. Conditions in western Illinois were noticeably drier with an average of 0.26 wfv; this is, however, still significantly above wilting points. The difference followed the precipitation patterns with southern Illinois having 3.40 inches of rain during the first two weeks of April.
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.
