Decatur County, Iowa Demographics

Population trends, housing costs, income, commuting, and health, all on one page.

Decatur County, IA Population Density Map and Area Scores

Area Score

Health, income and education, each graded from F to A+. Explore interactive maps for deeper analysis.

  • B
    Health Around average
    Less healthy than 91% of counties in Iowa
  • D
    Income Well below average
    Among the 3 least wealthy counties in Iowa
  • D
    Education Well below average
    Better educated than 78% of counties in Iowa

Source: Map AI Methodology

Decatur County
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Population density, people per sq mi

Population: density and quick facts

Metric Decatur County Iowa Avg U.S. Average
Population 7,759 3,204,793 337,468,954
Population density (per sq mi) 14.6 57.0 86.4
Population growth (%/yr) -0.70% 0.41% 0.59%
Median age 37.5 36.8 37.3
Households 3,055 1,308,457 130,235,071

Population in Decatur County declined by 6.8% from 2009 to 2024, reaching 7,759 in 2024.

Population Growth 2009–2024

Year Decatur County

Race & Ethnicity

Group Share

Age & Sex

The largest generation in Decatur County is Gen Z, aged 13–28, at 26.3% of residents. That is 4.0 points above Iowa as a whole.

Residents by birth cohort, from the 2025 age distribution. The right-hand figure is how far each cohort's share sits above or below Iowa, in percentage points. Children younger than Gen Z and the generations before the Boomers are counted in the population but not shown here, so these shares do not add up to 100%.

Male and female share

Women are 49.6% of the people living in Decatur County and men 50.4%.

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100% of everyone living in Decatur County

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Economy

Decatur County has a the economy index of D, which means it is barely prosperous.

Metric Decatur County Iowa Avg U.S. Average
Median household income $58,830 $75,133 $80,455
Income growth (%/yr) 5.54% 3.99% 4.80%
Unemployment rate 1.9% 3.6% 5.2%

The median household income in Decatur County is about 22% lower than in Iowa.

Detailed wealth and income breakdown →

Housing

Metric Decatur County Iowa Avg U.S. Average
Median home price $29,305 $153,425 $248,835
Median rent $610 $971 $1,407
Homeownership rate 69.7% 71.7% 65.2%

The median home price in Decatur County is about 4.0 years' worth of rent — buying at the median price costs roughly as much as paying the median rent of $611 per month for that long.

Full housing market analysis →

Commute Time & Mobility

Commuters in Decatur County spend about 32 minutes on the road round trip each working day. Over a typical 250-day work year, that adds up to roughly 133 hours, about 5.5 full days, spent commuting.

Metric Decatur County Iowa Avg U.S. Average
One-way commute (min) 15.9 17.0 22.4
Round-trip commute (min) 31.9 33.9 44.8
Yearly time spent (hours) 133 141 187
Estimated yearly cost $4,116 $4,382 $5,790
Work from home 6.0% 11.3% 15.0%
Highway traffic (vehicles/day) 3,953 4,993 8,813
Local road traffic (vehicles/day) 164 606 1,355

Fastest commutes among counties in Iowa: Sioux County (10.1 min), Union County (10.4 min), Cass County (10.6 min).
Slowest: Monroe County (30.4 min), Madison County (30.1 min), Mills County (26.7 min).

The average commute time in Decatur County is 16 minutes, shorter than the 17 minutes in Iowa.

Estimated yearly cost applies a single national wage rule of thumb (U.S. Bureau of Labor Statistics average hourly earnings), not a measurement of wages in this area. Traffic volume figures come from proprietary Ticon and TrafficZoom data.

Commute and transport details →

Education & Households

Decatur County has a education index of D, which means it is barely educated.

Metric Decatur County Iowa Avg U.S. Average
Bachelor's degree or higher 21.0% 27.9% 31.6%
Average household size 2.35 2.37 2.53

Highest education index among counties in Iowa: Johnson County (0.4), Dallas County (0.4), Story County (0.4).
Lowest: Crawford County (0.2), Wayne County (0.2), Louisa County (0.2).

Health

Decatur County has a health index of B, which means it is quite healthy.

Metric Decatur County Iowa Avg U.S. Average
Life expectancy (years) 78.7 79.2 78.3
Self-rated poor health 15.4% 13.6% 16.3%
Smokers 18.7% 17.6% 19.0%

Highest health index among counties in Iowa: Johnson County (0.8), Story County (0.8), Winneshiek County (0.8).
Lowest: Davis County (0.8), Wayne County (0.8), Appanoose County (0.8).

Full health data →

Frequently Asked Questions

Common questions about Decatur County, Iowa.

How big is Decatur County, Iowa by population?

About 7,759 people live in Decatur County, Iowa, in 3,055 households of 2.4 people on average. The median age is 37.5, close to the U.S. median of 37.3.

Is Decatur County, Iowa urban or rural?

Averaged over its land area, Decatur County, Iowa has 15 people per square mile, a density typical of rural areas. That is about 17% of the U.S. average of 86.

Is Decatur County, Iowa an affordable place to live?

The median home costs 0.5 times the median household income ($29,305 against $58,830), compared with 3.1 times nationally. That is within the traditional rule of thumb of about 3 times income. Median rent of $611 a month takes about 12% of the median household's income, below the 30% level at which HUD considers renters cost-burdened.

How strong is the job market in Decatur County, Iowa?

Unemployment in Decatur County, Iowa is only 1.9%, well below the U.S. rate of 5.2%, a sign of a tight labor market where employers compete for workers.

What share of adults in Decatur County, Iowa have a college degree?

21.0% of adults in Decatur County, Iowa hold a bachelor's degree or higher (about 1 in 5), well below the U.S. share of 31.6%.

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