Marathon is a city on Knight's Key, Boot Key, Key Vaca, Fat Deer Key, Long Point Key, Crawl Key and Grassy Keyislands in the middle Florida Keys, in Monroe County, Florida, in the United States. As of the 2000 census, the city had a total population of 10,255. As of 2005, the population estimated by the U.S. Census Bureau is 10,626.
Location in Monroe County and the state of Florida
U.S. Census Bureau map showing city limits
Marathon is located at 24.7 north and 81.04 west.
According to the United States Census Bureau, the city has a total area of 9.6 square miles (25 km2), of which 8.6 square miles (22 km2) is land and 1.0 square mile (2.6 km2) (10.37%) is water. Its city limits extend 1200' from land into the adjacent waters.
Marathon has a tropical climate (Aw in the koppen and Trewartha climate classifications). There is no record of snow/frost/freeze in Marathon. Like much of south Florida and the Florida Keys, Marathon has two seasons; A hot and wet season from May through October, and a warm and dry season from November though April.