Soil Moisture Levels Increased in Early May

[May 19, 2015]  CHAMPAIGN - Soil moisture increased slightly throughout the state the first half of May, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program Manager at the Illinois State Water Survey, Prairie Research Institute, University of Illinois.

Soil moisture levels at 2 inches averaged 0.35 water fraction by volume (wfv) on May 15, an increase of 26 percent in the first two weeks of the month. The largest change was in west central Illinois where 2 inch moisture levels increased 68 percent over the same time period. Similar, though slighter, changes were observed at 4- and 8-inch depths.

Rain from the weekend had no significant impact, on average, on soil moisture levels. However, significant increases were seen at several locations. The Dixon Springs Agricultural Center in southern Illinois recorded 2.66 inches of rain May 15–17, which resulted in a 50 percent increase in soil moisture at 2 inches.

Moisture levels remained high at 20 inches and greater, averaging 0.43 wfv at 59 inches.

Soil temperatures were near normal for the first half of May with a statewide average of 73.2 degrees F on May 17 at 2 inches under bare soil. Temperatures were slightly lower at deeper depths with averages of 70.6 degrees at 4 inches under bare soil, 68.7 degrees at 4 inches under sod, and 66.1 degrees at 8 inches under sod.

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.

[Lisa A. Sheppard, Illinois State Water Survey]