Washington County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 27th-largest in Iowa
The population of Washington County, Iowa is 22,539 as of the 2023 American Community Survey, making it the 27th-largest county in Iowa. The median household income is $71,339, the median home value is $199,600, and the median age is 40.3.
The population of Washington County has grown 4.4% since 2010 (21,687 → 22,631), a +0.30% annualized rate.
22,539
Population
+0.30%
Annual growth
40
People / sq mi
$71,339
Median Income
$199,600
Median Home Value
Washington County covers 569 sq mi of land at 39.6 people per square mile.
About Washington County, IA
The poverty rate is what most separates Washington County from the typical county: 6.0% of residents live below the federal poverty line, against 12.4% nationally. Washington County is a county in Iowa with a population of 22,539. It ranks #27 among counties in Iowa by population.
The typical household earns $71,339 a year, below the US median of $78,538. Only 6.0% of residents live in poverty, below the national 12.4%. Median home value is $199,600, with typical rent around $862.
Roughly 24.9% of adults have a bachelor’s, below the national 35.0%. Remote work is below the national 14.0% at 8.5%, and the average commute runs about 24 minutes each way.
Washington County Population History (2010-2024)
The county of Washington County had a population of 21,687 in 2010 and 22,631 in 2024, a 4.4% growth over 14 years. The peak was 22,631 in 2024. Average annual growth rate: 0.31%.
22,631
Population (2024)
21,687
Population (2010)
22,631
Peak (2024)
0.31%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 21,687 |
| 2011 | 21,825 |
| 2012 | 21,910 |
| 2013 | 21,954 |
| 2014 | 22,040 |
| 2015 | 22,160 |
| 2016 | 22,147 |
| 2017 | 22,236 |
| 2018 | 22,095 |
| 2019 | 22,030 |
| 2020 | 22,541 |
| 2021 | 22,526 |
| 2022 | 22,541 |
| 2023 | 22,554 |
| 2024 | 22,631 |
Race & Ethnicity
| White | 91.3% |
| Black or African American | 0.6% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.1% |
| Two or More Races | 0.0% |
Age & Sex
40.3
Median Age
50.3%
Female
49.7%
Male
19.9%
Age 65+
Age Distribution
Children (under 15): 20.3% · Seniors (65+): 19.9%
Income & Poverty
| Median household income | $71,339$-1,808 vs state |
| Mean household income | $92,270 |
| Per-capita income | $37,686 |
| Poverty rate | 6.0%-0.9% vs state |
| Unemployment rate | 1.7% |
| Employment-to-population | 66.4% |
Top Industries by Employment
The largest employment sector in Washington County is professional & business services, accounting for 25.2% of workers.
How residents commute
1.0%
Drive alone
2.5%
Carpool
77.8%
Public transit
8.5%
Work from home
24.2 min
Avg commute
Housing
$199,600+$3,700 vs state
Median home value
$862
Median rent
72.2%
Homeownership rate
9,638
Total housing units
93.9%
Occupied
6.1%
Vacant
27.8%
Renter-occupied
Social & access
92.8%
With health insurance
92.5%
With broadband internet
18.0%
Foreign-born
6.2%
Veterans (18+)
13.5%
With a disability
92.8%
Speak language other than English at home
Education
93.2%
High School+
24.9%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
Metro areas in Iowa
County rankings
Frequently Asked Questions
Washington County, Iowa has a population of 22,539 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 27th-largest county in Iowa. Population density is 40 people per square mile.
The population of Washington County has grown 4.4% since 2010 (21,687 → 22,631), a +0.30% annualized rate.
The median household income in Washington County, Iowa is $71,339, with mean (average) household income of $92,270 and per-capita income of $37,686. 6.0% of residents live below the federal poverty level.
In Washington County, the largest racial and ethnic groups are White (91.3%), Hispanic or Latino (1.1%), Black or African American (0.6%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Washington County, Iowa is 40.3 years. Residents are 50.3% female and 49.7% male.
The median home value in Washington County is $199,600 and median monthly rent is $862. 72.2% of occupied housing units are owner-occupied. The county has 9,638 total housing units, 6.1% of which are vacant.
The largest employment sector in Washington County, Iowa is professional, scientific, and management services, employing 25.2% of workers. The unemployment rate is 1.7%.
Des Moines is among the largest cities associated with Washington County, Iowa, with a population of 212,464.
Washington County, IA Climate
Washington County, IA has an average annual temperature of 10.1°C (50°F) and receives about 910 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
10.1°C
Avg Temp
910
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -6° / 21° | 30 mm |
| February | -3° / 27° | 27 mm |
| March | 4° / 39° | 60 mm |
| April | 11° / 51° | 81 mm |
| May | 17° / 62° | 112 mm |
| June | 22° / 72° | 107 mm |
| July | 24° / 76° | 111 mm |
| August | 23° / 73° | 107 mm |
| September | 18° / 65° | 103 mm |
| October | 12° / 53° | 68 mm |
| November | 4° / 39° | 60 mm |
| December | -3° / 26° | 44 mm |
1970–2000 normals from WorldClim 2.1 (~9 km grid). Precipitation can be less precise near mountains or coastlines, where rainfall varies sharply over short distances.
Best time to visit Washington County, IA
The most comfortable months to visit Washington County, IA are typically June, August and September, when temperatures are mildest and rainfall is relatively low. The hottest month is July (around 30°C high). The coldest is January (near -11°C low). May is usually the wettest month.
Where to stay near Washington County
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Population, race, income, age, and trends across Iowa
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.