Longmont, CO ZIP codes
Longmont, Colorado has 4 ZIP codes, including 1 PO Box ZIP. They are in Boulder County and Weld County.
- Population in these ZIPs
- 143,444
- Avg. median income
- $103,600population-weighted
- Typical home value
- $580,700population-weighted
- Metro area
- Boulder, CO
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Longmont, CO ZIP codes list
| ZIP code | County | Population | Median income | Typical home value |
|---|---|---|---|---|
| 80501 | Boulder County | 44,147 | $80,911 | $478,600 |
| 80502 PO Box | Boulder County | — | — | — |
| 80503 | Boulder County | 35,846 | $113,620 | $726,900 |
| 80504 | Weld County | 63,451 | $113,643 | $569,200 |
Population and median household income: ACS 2020–2024 5-year estimates. Typical home value: Zillow Home Value Index (September 2026) where available, otherwise the ACS median owner-reported value. "PO Box" marks ZIP codes with no delivery area of their own. Methodology
Cities near Longmont
Frequently asked questions
What county is Longmont, Colorado in?
Longmont ZIP codes are in Boulder County and Weld County.
Which Longmont ZIP codes are PO Boxes?
80502 is a PO Box or single-organization ZIP code; it has no residential delivery area.