Longmont, Colorado

4 ZIP codes · Mountain time

ZIP codes (largest first)

80504 · 63,45180501 · 44,14780503 · 35,84680502 (PO box)
Population99,406
StateColorado
CountyWeld County, Boulder County
Time zoneMountain
Land area29.26 sq mi

Area codes in this area

303720983

These are the area codes that most often serve Longmont (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 Longmont

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