Soil temperatures at depths of 4 inches under
sod averaged 75.8 degrees in Illinois during the first half of
August, 1.2 degrees below the long-term average and 4.0 degrees
lower than the same period in 2016. Daily highs reached the
mid-90s with lows in the 60s. This follows the trends seen with
air temperatures that are 3.6 degrees below normal as of August
Temperatures were also lower under bare soil, averaging 77.9
degrees at 2 inches and 77.4 degrees at 4 inches.
August has also been dry. Precipitation for the month was 1.00
inch below the long-term average as of August 15. The drier
weather has led to lower soil moisture levels throughout the
state with the largest decreases seen in northern and east
central Illinois. Soil moisture levels declined 11 percent at
depths of 2 inches to a state average of 0.18 water fraction by
volume (wfv) on August 15.
There were similar declines at depths from 4 to 20 inches. Soil
moisture levels remained steady at 39 and 59 inches, averaging
0.41 and 0.40 wfv, respectively, on August 15.
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
[Lisa A. Sheppard]
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.