The ISWS Water and Atmospheric Resources Monitoring program records
soil temperatures at 4 and 8 inches under grass at 19 sites across
the state. In addition, 4-inch bare soil temperatures are computed
to represent a cultivated field. These data for the past seven days
are available in map and tabular form at
4-inch soil temperatures under grass during the day are into the
upper 40s in northern Illinois, the low to mid 50s in central
Illinois, and the mid 50s in southern Illinois. At night they are
cooling off by about 4 to 6 degrees.
"The statewide soil temperatures give a general idea of
conditions; however, soil temperatures in an individual field will
depend on factors such as soil moisture and tillage practices,"
Angel said. "Also, soil temperatures at the surface will warm up and
cool off much faster than in deeper layers."
The Illinois State Water Survey, a division of the Institute of
Natural Resource Sustainability at the University of Illinois at
Urbana-Champaign, is the primary agency in Illinois concerned with
water and atmospheric resources.
[Text from file received from
State Water Survey]