Longmont city, Colorado
Official LSAD Designation: Longmont city • Census GEOID: 0845970
• Boulder County / Weld County
Demographics & Population Profile
Population and demographics for Longmont city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 100,109 | — | 2025 | Census |
| Median Age | 40.3 yrs | ±0.7 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 42,155 | ±872 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).