Black Diamond city, Washington
Official LSAD Designation: Black Diamond city • Census GEOID: 5306330
• King County
Demographics & Population Profile
Population and demographics for Black Diamond city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 6,978 | — | 2025 | Census |
| Median Age | 38.1 yrs | ±3.9 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 2,316 | ±153 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).