Polk County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 1st-largest in Iowa
The population of Polk County, Iowa is 497,441 as of the 2023 American Community Survey, making it the 1st-largest county in Iowa. The median household income is $81,621, the median home value is $248,400, and the median age is 36.2.
The population of Polk County has grown 19.4% since 2010 (432,360 → 516,185), a +1.27% annualized rate.
497,441
Population
+1.27%
Annual growth
869
People / sq mi
$81,621
Median Income
$248,400
Median Home Value
Polk County covers 573 sq mi of land at 868.6 people per square mile.
About Polk County, IA
Polk County stands apart on settlement density — it is among the most densely settled of US counties, at roughly 869 people per square mile. Polk County is a county in Iowa with a population of 497,441. It is the #1-largest of all counties in Iowa nationally.
Households take in a median $81,621, comfortably near the US median of $78,538. About 7.1% of residents live below the federal poverty level, below the national 12.4%. Home values run above average at $248,400, with typical rent around $1,113.
Degree attainment is near the top of the range for US counties: 39.5% of adults 25+ hold a bachelor’s, above the 35.0% national rate. About 13.9% of workers primarily work from home, close to the national 14.0%, and the average commute runs about 20 minutes each way.
That density explains much of the rest of the profile in Polk County: denser places lean toward renting, shorter commutes by transit, and a younger working-age mix.
Polk County Population History (2010-2024)
The county of Polk County had a population of 432,360 in 2010 and 516,185 in 2024, a 19.4% growth over 14 years. The peak was 516,185 in 2024. Average annual growth rate: 1.27%.
516,185
Population (2024)
432,360
Population (2010)
516,185
Peak (2024)
1.27%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 432,360 |
| 2011 | 438,783 |
| 2012 | 444,753 |
| 2013 | 452,780 |
| 2014 | 461,069 |
| 2015 | 467,517 |
| 2016 | 474,593 |
| 2017 | 480,962 |
| 2018 | 486,222 |
| 2019 | 491,031 |
| 2020 | 493,039 |
| 2021 | 497,903 |
| 2022 | 501,261 |
| 2023 | 507,487 |
| 2024 | 516,185 |
Race & Ethnicity
| White | 77.8% |
| Black or African American | 7.5% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.2% |
| Two or More Races | 0.0% |
Age & Sex
36.2
Median Age
50.3%
Female
49.7%
Male
13.7%
Age 65+
Age Distribution
Children (under 15): 20.4% · Seniors (65+): 13.7%
Income & Poverty
| Median household income | $81,621+$8,474 vs state |
| Mean household income | $106,356 |
| Per-capita income | $44,008 |
| Poverty rate | 7.1%+0.2% vs state |
| Unemployment rate | 3.1% |
| Employment-to-population | 67.9% |
Top Industries by Employment
The largest employment sector in Polk County is professional & business services, accounting for 21.0% of workers.
How residents commute
0.6%
Drive alone
1.4%
Carpool
74.1%
Public transit
13.9%
Work from home
19.9 min
Avg commute
Housing
$248,400+$52,500 vs state
Median home value
$1,113
Median rent
67.1%
Homeownership rate
215,016
Total housing units
94.1%
Occupied
5.9%
Vacant
32.9%
Renter-occupied
Social & access
95.1%
With health insurance
96.0%
With broadband internet
21.9%
Foreign-born
6.0%
Veterans (18+)
11.2%
With a disability
85.4%
Speak language other than English at home
Education
92.5%
High School+
39.5%
Bachelor's+
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County rankings
Common questions about Polk County, IA
Frequently Asked Questions
Polk County, Iowa has a population of 497,441 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 1st-largest county in Iowa. Population density is 869 people per square mile.
The population of Polk County has grown 19.4% since 2010 (432,360 → 516,185), a +1.27% annualized rate.
The median household income in Polk County, Iowa is $81,621, with mean (average) household income of $106,356 and per-capita income of $44,008. 7.1% of residents live below the federal poverty level.
In Polk County, the largest racial and ethnic groups are White (77.8%), Black or African American (7.5%), Hispanic or Latino (1.2%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Polk County, Iowa is 36.2 years. Residents are 50.3% female and 49.7% male.
The median home value in Polk County is $248,400 and median monthly rent is $1,113. 67.1% of occupied housing units are owner-occupied. The county has 215,016 total housing units, 5.9% of which are vacant.
The largest employment sector in Polk County, Iowa is professional, scientific, and management services, employing 21.0% of workers. The unemployment rate is 3.1%.
Des Moines is among the largest cities associated with Polk County, Iowa, with a population of 212,464.
Polk County, IA Climate
Polk County, IA has an average annual temperature of 9.5°C (49°F) and receives about 871 mm of precipitation per year. The warmest month is July and the coldest is January. Figures are 1970–2000 climate normals.
9.5°C
Avg Temp
871
Precip (mm/yr)
Jul
Hottest Month
Jan
Coldest Month
| Month | Avg (°C/°F) | Precip |
|---|---|---|
| January | -7° / 19° | 25 mm |
| February | -4° / 25° | 28 mm |
| March | 3° / 37° | 57 mm |
| April | 10° / 50° | 88 mm |
| May | 16° / 62° | 108 mm |
| June | 22° / 71° | 120 mm |
| July | 24° / 75° | 104 mm |
| August | 23° / 73° | 105 mm |
| September | 18° / 64° | 87 mm |
| October | 11° / 52° | 67 mm |
| November | 3° / 37° | 49 mm |
| December | -4° / 24° | 33 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 Polk County, IA
The most comfortable months to visit Polk 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 -12°C low). June is usually the wettest month.
Where to stay near Polk County
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.