Mean annual precipitation ranges from 25 to 29 inches, and mean annual temperature ranges from 63 to 67 degrees F. Frost free days range from 220 to 240 days, and elevation ranges from 1,150 to 1,950 feet. Thornthwaite P-E indices are 34 to 44. These are the competing Rowena series, and the Frio, Leeray, Nuvalde, and Throck series. Frio, Nuvalde, and Throck soils, when dry, do not have cracks as wide as 1 cm at 20 inches depth. Leeray soils have intersecting slickensides and gilgai microrelief.
Permeability is slow.
Runoff is low on slopes less than 1 percent and medium on 1 to 5 percent slopes. Small grains, forage sorghums, and grain sorghums are the main crops. Coastal bermudagrass and Kleingrass are the main pasture grasses. Native vegetation is mostly sideoats grama, Texas wintergrass, buffalograss, pricklypear, mesquite, and liveoak. Rolling Limestone Prairies and North Central Prairie of Texas.