Longmont, Colorado ZIP Codes

ZIP records
3
Sum of listed ZIP population estimates
143,444
Counties represented
2
Population range
35,846–63,451 per ZIP

Population sum includes positive estimates in these ZIP records; it is not an official city population.

Top ZIP Codes by Population

Rank	ZIP Code	City	County	Population estimate
1	80504	Longmont	Weld	63,451
2	80501	Longmont	Boulder	44,147
3	80503	Longmont	Boulder	35,846

Counties represented

Boulder County
Weld County

All ZIP Codes in Longmont

ZIP 80501 — Boulder County
ZIP 80503 — Boulder County
ZIP 80504 — Weld County

Browse all ZIP data for Colorado

Methodology: ZIP records are grouped by the source file's primary city and state fields. Population ranges and sums use positive ZIP-level estimates; sums should not be read as official city totals. County links use each record's listed county assignment.