Monmouth, Iowa Demographics & Population 2026

A note before these figures: with a population of 121, Monmouth'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

Monmouth is a small community located in Iowa, within Jackson County. The total population is 121. It ranks as the 823rd most populous out of 1,017 Census-designated places in Iowa.

Age Demographics

The median age in Monmouth is 56.5 years. This is 46% higher than the state median of 38.6 years. Only 9.1% of residents are under 18, indicating fewer families with children.

Economy, Income & Housing

The median household income in Monmouth is $51,875. This is 31% lower than the state median of $75,059. It is also 36% lower than the national median of $80,734. The poverty rate stands at 18.2%. This is 64% higher than the state poverty rate of 11.1%. The unemployment rate is 1.5%. This is 57% lower than the state rate of 3.6%. The median home value is $66,700. Housing costs are 68% lower than the state median of $208,000. With a home-value-to-income ratio of just 1.3x, Monmouth is one of the most affordable housing markets in the area. 91.2% of occupied housing units are owner-occupied. This homeownership rate is 27% higher than the state average of 71.7%.

Race & Ethnicity

Every resident counted in Monmouth 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

6.8% of residents aged 25 and older hold a bachelor's degree or higher. This is 78% 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 88.3%.

Data Sources & Methodology

All demographic data for Monmouth, 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.