Herndon, VA -- U.S. town in Virginia Population (2000): 21655 Housing Units (2000): 7190 Land area (2000): 4.221306 sq. miles (10.933133 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 4.221306 sq. miles (10.933133 sq. km) FIPS code: 36648 Located within: Virginia (VA), FIPS 51 Location: 38.971478 N, 77.388675 W ZIP Codes (1990): 22070 22071 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Herndon, VA Herndon