On these dissected plains, the broad divides are nearly level to gently sloping, but slopes are short and steep in the valleys. In places the valleys are bordered by a rolling to steep irregular dune topography. Local relief is mainly in meters, but a few of the larger valleys are tens of meters or more below the general level of the plain. In southwestern Oklahoma, the Wichita Mountains are as much as 300 m above the surrounding plains. Average annual precipitation - 500 to 750 mm, increasing from west to east.
Maximum precipitation is in spring, and the minimum is in winter.
Snowfall ranges from 25 cm in the north to 10 cm in the south. The moderate but somewhat erratic precipitation supplies water for range and crops. Small ponds on individual farms provide water for livestock. Some larger ponds on individual farms are used for flood control, recreation, irrigation water, or water for livestock. A few large ponds and reservoirs are a source of municipal water and irrigation water.