| County : | Jefferson County |
| State : | Illinois (IL) |
| Land Area : | 571.17 sq mi |
| Water Area : | 12.62 sq mi |
| Latitude : | 38.3007796 |
| Longitude : | -88.9242100 |
| Population (2010): | 38,827 |
| Population Estimate (2012) : | 38,908 |
| Population Density : | 67.98/sq mi |
| Housing Units (2012) : | 16,954 |
| Median Household Income (2012) : | $42,272 (Illinois : $56,853, USA : $53,046) |
| Median Family Income (2012) : | $54,632 (Illinois : $70,144, USA : $64,585) |
| Median House Price (2012) : | $86,000 (Illinois : $190,800, USA : $181,400) |
Jefferson County Cities / Towns
| Belle Rive Village (361) | Bluford Village (688) | Bonnie Village (397) |
| Dix Village (461) | Ina Village (2,338) | Mount Vernon City (15,277) |
| Nason City (236) | Opdyke (254) | Waltonville Village (434) |
| Woodlawn Village (698) |
Jefferson County Zip Codes
| 62801 (22,415) | 62808 (1,457) | 62810 (1,089) |
| 62814 (2,124) | 62816 (1,306) | 62830 (1,392) |
| 62846 (2,631) | 62851 (329) | 62864 (24,108) |
| 62872 (1,178) | 62877 (514) | 62883 (591) |
| 62889 (851) | 62893 (977) | 62894 (1,006) |
| 62898 (2,097) |