31320 -- U.S. ZIP code Municipality (1990): MIDWAY, Georgia All ZIPs for this municipality (1990): 31320 Population (2000): 6896 Housing Units (2000): 3141 Land area (2000): 151.465134 sq. miles (392.292880 sq. km) Water area (2000): 1.021392 sq. miles (2.645392 sq. km) Total area (2000): 152.486526 sq. miles (394.938272 sq. km) Located within: Georgia (GA) Location: 31.788811 N, 81.376373 W