Physical Characteristics. Dade County is in south Florida and is bordered by Monroe, Broward, and Collier counties and the Atlantic Ocean. The county has 1955.26 square miles of land and 64.25 square miles of water for a total of 2019.51 square miles. The average January temperature is 67.9 degrees Fahrenheit, and the average August temperature is 82.1 degrees Fahrenheit. The average annual rainfall is 57.77 inches.
History. Dade County was established in 1836 from a portion of St. Johns county and named for Major Francis Longhorne Dade, U.S. Army Commander during the Second Seminole War.
