Kemah, Texas. Kemah (/ˈkiːmə/ KEE-ma) is a city in the U.S. state of Texas, southeast of Houston along west Galveston Bay. The city's population was 1,773 at the 2010 census, down from 2,330 at the 2000 census. Located in Galveston County, Kemah's main industry is shipping.