population herrin, il
Herrin is located in Williamson County in Illinois. 1  Population: 12,524. 2  Area: 9.47 sq. miles Land Area: 9.24 sq. miles. 3  Population Density: 1,323.05 people per sq. mile.  Elevation: 419.62 1  ft. Time Zone: Central Standard Time (GMT 2  -6) Daylight Savings:  Yes.