The area was named for William E. Throckmorton, an early settler on the north Texas frontier. Hills are prominent in the southwestern sections. The county is in the Rolling Plains vegetation region and is covered by bluestem, gramas, wildryes, and wheat grass, along with some mesquite trees.
Annual rainfall averages twenty-six inches.
Temperatures range from an average minimum of 29 F in January to an average maximum of 98 in July. The average growing season lasts 220 days. The major arteries of the area's transportation network are U.S. Highway 380, U.S. Highway 283, and State Highway 79, which crosses through the northeastern part of the county to the town of Throckmorton. Mineral resources in the county include limestone, sand and gravel, petroleum, natural gas, and bituminous coal. The area that is now Throckmorton County was a part of Red River Municipality until 1837, when it became part of mewly organized Fannin County.