Castalia, Iowa Demographics & Population 2026

A note before these figures: with a population of 142, Castalia'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

Castalia is a small community located in Iowa, within Winneshiek County. The total population is 142. It ranks as the 781st most populous out of 1,017 Census-designated places in Iowa.

Age Demographics

The median age in Castalia is 58.0 years. This is 50% higher than the state median of 38.6 years. Only 8.5% of residents are under 18, indicating fewer families with children. 12.7% 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 Castalia is $61,250. This is 18% lower than the state median of $75,059. It is also 24% lower than the national median of $80,734. The poverty rate stands at 7.9%. This is 29% lower than the state poverty rate of 11.1%. The survey records no unemployed residents in Castalia, which reflects the size of the sample rather than a labor market without joblessness. The median home value is $97,500. Housing costs are 53% lower than the state median of $208,000. With a home-value-to-income ratio of just 1.6x, Castalia is one of the most affordable housing markets in the area. 93.1% of occupied housing units are owner-occupied. This homeownership rate is 30% higher than the state average of 71.7%.

Race & Ethnicity

Every resident counted in Castalia was recorded as White (non-Hispanic). A figure of exactly 100.0% reflects a survey sample too small to capture the community's full composition rather than a precise measurement.

Education

9.8% of residents aged 25 and older hold a bachelor's degree or higher. This is 69% 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 89.3%.

Data Sources & Methodology

All demographic data for Castalia, 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.