Auburn, IL -- U.S. city in Illinois Population (2000): 4317 Housing Units (2000): 1753 Land area (2000): 3.155706 sq. miles (8.173240 sq. km) Water area (2000): 0.000000 sq. miles (0.000000 sq. km) Total area (2000): 3.155706 sq. miles (8.173240 sq. km) FIPS code: 02921 Located within: Illinois (IL), FIPS 17 Location: 39.588969 N, 89.745962 W ZIP Codes (1990): 62615 Note: some ZIP codes may be omitted esp. for suburbs. Headwords: Auburn, IL Auburn