Barnum, IA -- U.S. city in Iowa Population (2000): 195 Housing Units (2000): 70 Land area (2000): 0.316622 sq. miles (0.820046 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.316622 sq. miles (0.820046 sq. km) FIPS code: 04645 Located within: Iowa (IA), FIPS 19 Location: 42.506660 N, 94.364575 W ZIP Codes (1990): 50518 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Barnum, IA Barnum