The plains are notably flat, but there are occasional valleys, canyons, and buttes. In the northern section, badlands and isolated mountains break the continuity of the plains. Shortgrass prairie and badland topography along Little Missouri River, North Dakota. The climate of the Great Plains grasslands is a semiarid continental regime.
Winters are cold and dry, and summers are warm to hot.
The frost-free season ranges from fewer than 100 days in the north to more than 200 days in Oklahoma. Evaporation usually exceeds precipitation, and the total supply of moisture is low. When precipitation does occur, it is often in the form of hail or blizzards, and tornadoes and dust storms are frequent. The steppe in this province is dry, with 6-7 arid months per year. The Great Plains grasslands east of the Rockies have scattered trees and shrubs, such as sagebrush and rabbitbrush, and support all gradations of cover, from semidesert to woodland.