St. Marys, Iowa Demographics & Population 2026
During the 2020–2024 ACS period, St. Marys, Iowa had a total population of 96, the 864th largest city in Iowa, with a median household income of $77,500, which is 3% higher than the state average. The poverty rate is 8.3%.
Data vintage: U.S. Census Bureau ACS 2020–2024 5-Year Estimates · refreshed July 2026 · Methodology & source notes
Key Takeaways
- Unemployment rate of 10.2% is notably above the national average.
St. Marys Quick Facts
How St. Marys Changed
Change from the 2019–2023 ACS period to 2020–2024. These are rolling five-year estimates, not year-over-year measurements.
| Metric | 2019–2023 | 2020–2024 | Change |
|---|---|---|---|
| Population | 112 | 96 | -14.3% |
| Median household income | $78,750 | $77,500 | -1.6% |
| Median home value | $168,800 | $195,000 | +15.5% |
How St. Marys Compares
Median Household Income
Median Home Value
Economy & Housing
Household Income Distribution
Detailed income brackets
Employment
Housing Overview
People & Demographics
Age Distribution
Race & Ethnicity
Diversity Index
A less diverse community where one racial or ethnic group represents a large majority.
State average: 31 | National average: 61
Education
Educational Attainment (Adults 25+)
St. Marys Rankings in Iowa
Explore Iowa Rankings
Other Cities in Warren County
| City | Population | Median Income | Poverty | Home Value |
|---|---|---|---|---|
| Indianola | 16,044 | $75,453 | 6.4% | $237,500 |
| Hartford | 760 | $70,000 | 7.1% | $176,700 |
| Milo | 731 | $79,904 | 1.6% | $153,100 |
| New Virginia | 587 | $77,188 | 1.4% | $180,600 |
| Martensdale | 569 | $57,500 | 10.2% | $181,400 |
| Cumming | 545 | $162,875 | 4.4% | $508,000 |
| Lacona | 354 | $70,100 | 10.7% | $97,500 |
| Ackworth | 75 | $111,094 | 28.0% | $237,500 |
| Sandyville | 44 | N/A | 2.3% | $187,500 |
| Spring Hill | 39 | $86,250 | 7.7% | N/A |
Cities Similar to St. Marys
These cities in the same state have comparable population and economic profiles.
| City | Population | Median Income | Home Value | Bachelor's+ | Poverty |
|---|---|---|---|---|---|
| East Amana | 91 | N/A | N/A | 0.0% | 87.9% |
| Rochester | 90 | N/A | $340,300 | 15.6% | 0.0% |
| Spragueville | 90 | $77,500 | $109,400 | 3.4% | 12.2% |
| McIntire | 89 | N/A | $55,000 | 5.1% | 23.6% |
| Morrison | 96 | $66,250 | $95,000 | 19.7% | 17.7% |
A note before these figures: with a population of 96, St. Marys'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
St. Marys is a small community located in Iowa, within Warren County. The total population is 96. It ranks as the 864th most populous out of 1,017 Census-designated places in Iowa.
Age Demographics
The median age in St. Marys is 55.5 years. This is 44% higher than the state median of 38.6 years. Only 3.1% of residents are under 18, indicating fewer families with children.
Economy, Income & Housing
The median household income in St. Marys is $77,500. This is 3% higher than the state median of $75,059. It is also 4% lower than the national median of $80,734. The poverty rate stands at 8.3%. This is 25% lower than the state poverty rate of 11.1%. The unemployment rate is 10.2%. This is 184% higher than the state rate of 3.6%. The median home value is $195,000. Housing costs are 6% lower than the state median of $208,000. With a home-value-to-income ratio of just 2.5x, St. Marys is one of the most affordable housing markets in the area. 68.2% of occupied housing units are owner-occupied. This homeownership rate is 5% lower than the state average of 71.7%.
Race & Ethnicity
St. Marys has a predominantly White (non-Hispanic) population, comprising 97.9% of all residents.
Education
23.2% of residents aged 25 and older hold a bachelor's degree or higher. This is 26% 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 86.6%.
Data Sources & Methodology
All demographic data for St. Marys, 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.
Free data download: Get all Iowa city and county demographics as CSV. Download Cities CSV | Download Counties CSV
Frequently Asked Questions
What is the population of St. Marys, Iowa?
St. Marys, Iowa has a population of 96 according to the most recent U.S. Census ACS 5-Year Estimates.
What is the median household income in St. Marys, IA?
The median household income in St. Marys is $77,500, which is 4% lower than the national median of $80,734.
What is the poverty rate in St. Marys, IA?
The poverty rate in St. Marys is 8.3%. This means approximately 8 residents live below the federal poverty line.
What is the racial makeup of St. Marys, Iowa?
St. Marys's population is 97.9% White, 0.0% Black, 0.0% Hispanic/Latino, and 0.0% Asian.
What is the median home value in St. Marys, IA?
The median home value in St. Marys is $195,000. The home-value-to-income ratio is 2.5x.
How educated is St. Marys, Iowa?
23.2% of adults (25+) in St. Marys hold a bachelor's degree or higher, and 8.5% hold a graduate or professional degree.