Decorah, IA -- U.S. city in Iowa Population (2000): 8172 Housing Units (2000): 2968 Land area (2000): 6.405098 sq. miles (16.589128 sq. km) Water area (2000): 0.025032 sq. miles (0.064833 sq. km) Total area (2000): 6.430130 sq. miles (16.653961 sq. km) FIPS code: 19405 Located within: Iowa (IA), FIPS 19 Location: 43.301795 N, 91.790218 W ZIP Codes (1990): 52101 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Decorah, IA Decorah