September 26, 2021

Soils are drier for most of Illinois in mid-July

CHAMPAIGN, Ill. — Illinois soils have been drying out after the wet weather at the end of June, according to Jennie Atkins, Water and Atmospheric Resources Monitoring program manager at the Illinois State Water Survey.

Soil moisture levels have declined as most of the state dried out from a very wet end of June. Levels at the 4-inch depths have fallen an average of 5% so far in July. Only southern Illinois, which has received 3.46 inches of rain as of July 14, has seen overall soil moisture increases.

Soil moisture remains lower in northern Illinois than in other regions of the state. On July 14, levels averaged 0.21 water fraction by volume, 28% lower than in eastern Illinois and 42% lower than the in the west and south. However, conditions are still significantly improved from in June with northern Illinois levels averaging 31% higher than one month ago.

Soil temperatures at 4 inches under sod averaged 77 degrees in mid-July, equal to the historical average. Temperatures rose across the state the first week of the month to an average of 80 degrees on July 7 with highs in the mid-90s. Temperatures fell as the state experienced cooler weather July 9-11, but are beginning to rise again.

Overall, soil temperatures fell 2 degrees on average the first half of July at 4 inches under sod. Similar declines were also seen at 2 and 8 inches.

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 at www.isws.illinois.edu/warm and in the Illinois Water and Climate Summary at www.isws.illinois.edu/warm/climate.asp.