Washington County, Iowa Demographics 2026

Population Overview

Washington County is located in Iowa with a total population of 22,561. It is the 27th most populous county out of 99 in Iowa. The county encompasses 10 Census-designated places.

Age Demographics

The median age in Washington County is 40.7 years. This is 5% higher than the state median of 38.6 years.

Economy, Income & Housing

The median household income in Washington County is $75,647. This is about the same as the state median of $75,059. It is also 6% lower than the national median of $80,734. The poverty rate stands at 8.2%. This is 26% lower than the state poverty rate of 11.1%. The unemployment rate is 2.2%. This is 38% lower than the state rate of 3.6%. The median home value is $203,900. Housing costs are 2% lower than the state median of $208,000. With a home-value-to-income ratio of just 2.7x, Washington County is one of the most affordable housing markets in the area. 74.0% of occupied housing units are owner-occupied. This homeownership rate is 3% higher than the state average of 71.7%.

Race & Ethnicity

Washington County has a predominantly White (non-Hispanic) population, comprising 88.7% of all residents. Hispanic or Latino residents account for 7.8%. The Black or African American population (1.1%) is well below the state average of 3.8%. The Asian population (0.4%) is well below the state average of 2.5%.

Education

26.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 16% lower than the state rate of 31.4%. Nationally, 35.7% of adults hold at least a bachelor's degree. The high school graduation rate (or equivalent) is 93.5%.

Data Sources & Methodology

All figures for Washington County come from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates, with comparisons drawn against Iowa 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.