Thornton, Colorado

ZIP codes in Thornton

Area codes for Thornton

• Area code 303

  In service since 1947. Shares its area with 720 and 983. Local calls are dialed with ten digits; dialing 1 plus ten digits also works.

• Area code 720

  In service since June 1, 1998. Shares its area with 303 and 983. Local calls are dialed with ten digits; dialing 1 plus ten digits also works.

• Area code 983

  In service since June 17, 2022. Shares its area with 303 and 720. Local calls are dialed with ten digits; dialing 1 plus ten digits also works.

Area codes here are matched from telephone rate centers, so a place near a boundary can have local numbers from either side of it.

Time zone

Thornton is in the Mountain Time zone.

Towns near Thornton

• Welby3.1 km (1.9 mi)
• Federal Heights3.7 km (2.3 mi)
• Sherrelwood4.2 km (2.6 mi)
• Northglenn4.9 km (3.0 mi)
• Dupont5.2 km (3.2 mi)
• Derby5.6 km (3.5 mi)
• Shaw Heights5.9 km (3.7 mi)
• Westminster6.1 km (3.8 mi)