Monmouth, IA -- U.S. city in Iowa Population (2000): 180 Housing Units (2000): 77 Land area (2000): 0.561697 sq. miles (1.454789 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 0.561697 sq. miles (1.454789 sq. km) FIPS code: 53265 Located within: Iowa (IA), FIPS 19 Location: 42.076357 N, 90.880476 W ZIP Codes (1990): 52309 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Monmouth, IA Monmouth