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  5. Area Code 636

Where Is Area Code 636?

Area code 636 is found in the US state of Missouri. Primarily servicing the city of Saint Charles (population: 137739), area code 636 covers 9 counties of Missouri.

Located in the Central time zone, area code 636 is on the same time as Chicago, IL.

Area code 636 was brought into effect on May 22, 1999. 636 was split from the parent 314 area code.

Map of  with area code 636 highlighted

Counties in Area Code 636

  • Franklin,
  • Jefferson,
  • Lincoln,
  • Montgomery,
  • Saint Charles,
  • Saint Louis,
  • Warren,
  • Washington.

Most Populous Cities in Area Code 636

City County City Population Time Zone
Saint Charles Saint Charles 137,739 CST
Ballwin Saint Louis 92,744 CST
O Fallon Saint Charles 91,566 CST
Saint Peters Saint Charles 72,435 CST
Chesterfield Saint Louis 59,310 CST
Fenton Saint Louis 44,295 CST
Wentzville Saint Charles 36,561 CST
Arnold Jefferson 35,678 CST
Imperial Jefferson 26,609 CST
Festus Jefferson 26,572 CST
Troy Lincoln 23,698 CST
Washington Franklin 21,507 CST
De Soto Jefferson 20,853 CST
Lake Saint Louis Saint Charles 19,874 CST
Union Franklin 17,400 CST
High Ridge Jefferson 16,002 CST
Warrenton Warren 15,887 CST
Hillsboro Jefferson 15,822 CST
Pacific Franklin 15,657 CST
House Springs Jefferson 14,592 CST
Eureka Saint Louis 13,888 CST
Saint Clair Franklin 11,788 CST
Barnhart Jefferson 10,040 CST
Wright City Warren 9,839 CST
Grover Saint Louis 8,524 CST

Note: The above list is based off of the top 25 most populous cities in the area code as per 2012 United States Census Bureau estimates.

View all United States Area Codes.

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This page was last updated on July 3, 2015.