Onslow, Iowa Demographics & Population 2026

A note before these figures: with a population of 284, Onslow'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

Onslow is a small community located in Iowa, within Jones County. The total population is 284. It ranks as the 618th most populous out of 1,017 Census-designated places in Iowa.

Age Demographics

The median age in Onslow is 30.0 years. This is 22% lower than the state median of 38.6 years. With 39.1% of the population under 18, Onslow has a notably young demographic profile, suggesting a family-oriented community.

Economy, Income & Housing

The median household income in Onslow is $65,313. This is 13% lower than the state median of $75,059. It is also 19% lower than the national median of $80,734. The poverty rate stands at 29.2%. This is 164% higher than the state poverty rate of 11.1%. With more than one in five residents living below the poverty line, economic hardship is a significant challenge for the community. The survey records no unemployed residents in Onslow, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $100,000. Housing costs are 52% lower than the state median of $208,000. With a home-value-to-income ratio of just 1.5x, Onslow is one of the most affordable housing markets in the area. 79.2% of occupied housing units are owner-occupied. This homeownership rate is 10% higher than the state average of 71.7%.

Race & Ethnicity

Onslow has a predominantly White (non-Hispanic) population, comprising 90.8% of all residents. Black or African American residents account for 4.6%. The Hispanic or Latino population (2.8%) is well below the state average of 7.3%.

Education

14.8% of residents aged 25 and older hold a bachelor's degree or higher. This is 53% 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 99.3%.

Data Sources & Methodology

All demographic data for Onslow, Iowa 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 Iowa state averages and national averages calculated from the same dataset. Rankings reflect the city's position among all 1,017 Census-designated places in Iowa. Read more about how these figures are produced on our methodology page, or visit data.census.gov for official data.