Physical Characteristics. De Soto County is east of the Sarasota-Bradenton area and is bordered by Charlotte, Sarasota, Manatee, Hardee, and Highlands counties. The county has 635.73 square miles of land and 3.40 square miles of water for a total of 639.13 square miles. The average January temperature is 63.0 degrees Fahrenheit, and the average August temperature is 81.9 degrees Fahrenheit. The average annual rainfall is 50.66 inches.
History. De Soto County was established from a portion of Manatee County in 1887 and named for Spanish explorer Hernando de Soto.
