Columbia County's 2026 population is estimated at 3,965, reflecting a -0.75% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Columbia County is the 38th largest county in Washington. The 2010 population was 4,094 and has grown -3.15% since 2010.
Data after 2023 is projected based on recent change
Overall: 49.6 years
Female: 52.4 years
Male: 44.9 years
There are 3,291 adults, (1,177 of whom are seniors) in Columbia County.
Female: 2,016 (50.2%)
Male: 1,998 (49.8%)
The racial composition of Columbia County includes 83.13% White, 3.81% other race, and smaller percentages for Asian, Black or African American, Native American and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 3,337 | 83.13% |
| Two or more races | 414 | 10.31% |
| Other race | 153 | 3.81% |
| Asian | 75 | 1.87% |
| Black or African American | 22 | 0.55% |
| Native American | 13 | 0.32% |
Columbia County 's average per capita income is $53,611. Household income levels show a median of $71,810. The poverty rate stands at 9.31%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $108,608 | - |
| Families | $96,932 | $110,258 |
| Households | $71,810 | $88,239 |
| Non Families | $40,192 | $46,689 |
Average Income
Median Household Income
Poverty Rate