Bare soil temperatures, on average, rose more than 15 degrees
during the week with statewide averages of 63.0 degrees F for
2-inch depths and 61.5 degrees for 4 inches on April 16.
Temperatures under sod rose more slowly with temperatures at the
end of the week averaging 57.0 and 55.2 degrees at 4- and 8-inch
Increases occurred across the state. Temperatures in southern
Illinois rose 15.2 degrees, ending the week with a regional
average of 63.7 degrees at 2 inches under bare soil. The coolest
temperatures were in the north where 2-inch temperatures
averaged 60.1 degrees on April 16.
Soil moisture levels decreased slightly with the warmer weather.
Levels at a depth of 2 inches declined 13 percent, on average,
the second week of April to a statewide average of 0.31 water
fraction by volume (wfv). Levels at 4 inches also decreased to
0.32 wfv. No significant changes occurred at depths of 8 inches
and greater as levels remained near or above field capacity for
most of the soils monitored.
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
http://www.isws.illinois. edu/warm/ ) and in the
Illinois Water and Climate Summary (
http://www.isws.illinois.edu/ warm/climate.asp ).
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
[Lisa A. Sheppard]