Oso, Washington Demographics & Population 2026

A note before these figures: with a population of 245, Oso's ACS estimates come from a small number of survey responses and carry wide margins of error. Individual percentages below — particularly rates that round to 0% or 100% — are approximations, not precise measurements. See data.census.gov for the published margins of error.

Population Overview

Oso is a small community located in Washington, within Snohomish County. The total population is 245. It ranks as the 539th most populous out of 628 Census-designated places in Washington.

Age Demographics

The median age in Oso is 40.2 years. This is 5% higher than the state median of 38.3 years. With 33.1% of the population under 18, Oso has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Oso is $140,486. This is 43% higher than the state median of $98,141. It is also 74% higher than the national median of $80,734. The ACS records no residents below the poverty line in Oso. In a community this small the estimate rests on very few survey responses, so it should be read as an absence of measurement rather than a measured absence of poverty. The survey records no unemployed residents in Oso, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $741,100. Housing costs are 31% higher than the state median of $564,600. The home-value-to-income ratio is 5.3x. 100.0% of occupied housing units are owner-occupied. This homeownership rate is 57% higher than the state average of 63.8%.

Race & Ethnicity

The largest racial or ethnic group in Oso is White (non-Hispanic), making up 76.7% of the population. Hispanic or Latino residents account for 15.9%.

Education

9.7% of residents aged 25 and older hold a bachelor's degree or higher. This is 75% lower than the state rate of 39.6%. Nationally, 35.7% of adults hold at least a bachelor's degree. No surveyed resident aged 25 or older reported leaving school before earning a high school diploma, though a rate of exactly 100% reflects the limits of a small sample.

Data Sources & Methodology

All demographic data for Oso, Washington is sourced from the U.S. Census Bureau's American Community Survey (ACS) 2020–2024 5-Year Estimates. The ACS collects data from approximately 3.5 million households annually and pools five years of responses so that even small communities can be measured, though the margin of error widens as the population falls. Comparisons are made against Washington state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 628 Census-designated places in Washington. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.