Geographic Regions and Area Codes in Illinois

Illinois is divided into several key geographic regions, each with its own unique characteristics and area codes. The northeastern part of the state, which includes the Chicago metropolitan area, is one of the most significant regions due to its dense population and economic activity. Central Illinois includes cities like Springfield, Champaign-Urbana, and Decatur, while Southern Illinois encompasses areas such as Carbondale and the Metro East region of St. Louis suburbs.

Here are some of the major area codes in Illinois:

  • 312: Chicago
  • 773: Chicago
  • 872: Chicago
  • 217: Central Illinois, including Springfield and Champaign-Urbana
  • 618: Southern Illinois
  • 847: Northern suburbs of Chicago
  • 630: Western suburbs of Chicago