Johnstown, Colorado

1 ZIP code · Mountain time

ZIP codes (largest first)

80534 · 20,502
Population18,883
StateColorado
CountyWeld County
Time zoneMountain
Land area15.58 sq mi

Area codes in this area

970

These are the area codes that most often serve Johnstown (including overlays). The exact area code depends on the phone number — landlines, mobiles and overlays can differ even on the same street.

Find the ZIP+4 for an address in Johnstown

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Population: U.S. Census Bureau, ACS 5-year estimates, 2024.