309 Area Code is part of 19 counties in the state of Illinois. There are around 215 cities in the 309 area code. The 309 area code is located in the EST timezone. Illinois has an avarage population of 12,947,252 spread between the coordinates of +40.349457 Latitude and -88.986137 Longitude.
Below you will find more info about 309 Area Code and also zip codes, counties, cities and the post offices that belong to this Area Code.