CHAMPAIGN, Ill. - The mild winter weather has led to higher soil temperatures in comparison to last winter based on temperatures collected at weather stations across the state, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program Manager at the Illinois State Water Survey.

Soil temperatures are measured at depths of 4 inches under bare soil and at 4 and 8 inches under sod.  Sod generally acts as an insulator, causing soil temperatures to react more slowly to environmental changes.

The median soil temperature from November through January at depths of 4 inches under bare soil was 38.0 degrees, 4.7 degrees higher than the same period last year.  Similar increases were also seen for soil temperatures measured at 4 and 8 inches under sod.

The highest temperatures were observed in southern Illinois where the median soil temperature at 4 inches under bare soil was 42.1 degrees, 6.9  degrees higher than last winter.  The medians for central and northern Illinois, 36.7 degrees and 33.9 degrees respectively, were also higher than those of last winter. 

The Illinois State Water Survey’s Water and Atmospheric Resources Monitoring (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).  Hourly data can be obtained by contacting Jennie Atkins (sheppard@illinois.edu).

The Illinois State Water Survey at the University of Illinois at Urbana-Champaign, a division of the Prairie Research Institute, is the primary agency in Illinois concerned with water and atmospheric resources.