The mean annual temperature ranges from 45 to 54 degrees F, and mean annual precipitation ranges from 30 to 45 inches. These are the competing Harvard , Plano , St. Charles , and Virgil soils and the poorly drained Drummer soils. Harvard, Plano, and St. Charles soils are on nearby similar landscape. Virgil soils are generally less sloping and are somewhat poorly drained. Surface runoff is slow on the gentle slopes and rapid on the steeper slopes.
Permeability is moderate in the solum and moderate or moderately rapid in the substratum.
Most areas of these soils are cultivated. Native vegetation is a mixture of prairie grasses and trees. The extent is moderate. Kendall County, Illinois, 1941.