Jefferson County, Washington Demographics 2026

Population Overview

Jefferson County is located in Washington with a total population of 33,313. It is the 27th most populous county out of 39 in Washington. The county encompasses 6 Census-designated places.

Age Demographics

The median age in Jefferson County is 59.5 years. This is 56% higher than the state median of 38.2 years. Only 11.5% of residents are under 18, indicating fewer families with children. 15.3% of residents are 75 or older, suggesting a significant retirement-age population with implications for healthcare services and senior housing.

Economy, Income & Housing

The median household income in Jefferson County is $71,143. This is 25% lower than the state median of $94,952. It is also 9% lower than the national median of $78,538. The poverty rate stands at 12.6%. This is 27% higher than the state poverty rate of 9.9%. The unemployment rate is 7.7%. This is 54% higher than the state rate of 5.0%. The median home value is $495,100. Housing costs are 5% lower than the state median of $519,800. The home-value-to-income ratio of 7.0x suggests that housing affordability is a significant concern for many residents. 79.7% of occupied housing units are owner-occupied. This homeownership rate is 25% higher than the state average of 63.9%.

Race & Ethnicity

Jefferson County has a predominantly White (non-Hispanic) population, comprising 85.3% of all residents. Hispanic or Latino residents account for 4.3%. The Black or African American population (0.3%) is well below the state average of 3.8%. The Hispanic or Latino population (4.3%) is well below the state average of 14.1%. The Asian population (1.3%) is well below the state average of 9.3%.

Education

43.3% of residents aged 25 and older hold a bachelor's degree or higher. This places Jefferson County in the top 10% of all counties in the state for educational attainment. This is 12% higher than the state rate of 38.8%. Nationally, 35.0% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 96.1%. Notably, 19.7% of adults hold a graduate or professional degree, indicating a highly educated workforce.

Data Sources & Methodology

All figures for Jefferson County come from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates (2019-2023), with comparisons drawn against Washington and national averages from the same dataset. See our methodology page for how each metric is defined, or data.census.gov for official tables with margins of error.