Soil Moisture rises the second week of September

[September 23, 2015]  CHAMPAIGN – Soil moisture levels rose across Illinois the second week of September as the state saw increased rainfall and cooler soil temperatures, according to Jennie Atkins, Water and Atmospheric Resources Monitoring (WARM) Program Manager at the Illinois State Water Survey, Prairie Research Institute, University of Illinois.

Stations in the Illinois Climate Network (ICN) reported an average of 1.58 inches of rain from September 8 to 11, with stations in Springfield, Carbondale, and Brownstown (Fayette County) recording more than 3.50 inches during the time period.

The higher rainfall led to increases in soil moisture. On average, levels at 2 inches increased 54 percent from September 7 to 11 to a two-week high of 0.33 water fraction by volume (wfv). Levels declined slightly to an average of 0.27 wfv on September 15, well above the wilting point for most soil types. Similar trends were seen at depths of 4 and 8 inches.

Conditions remained wet at depths of 39 and 59 inches with little change seen at either depth.

Warmer weather brought higher than normal soil temperatures the first week of September. Temperatures averaged in the low to mid-80s from September 1 to 8, only to fall to the mid-60s during the second week. Temperatures under bare soil averaged 71.9 degrees at 2 inches and 71.6 degrees at 4 inches on September 15.

Soil temperatures under sod followed similar trends though the declines were slightly less. On September 15, temperatures averaged 69.5 and 69.4 degrees at 4 and 8 inches, respectively.

The Illinois State Water Survey's WARM Program collects hourly and daily weather and soil information at 19 stations across the state. Hourly, daily, and monthly data 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.

[Lisa Sheppard, State of Illinois Water Survey]