Iowa county populations
99 supported county-equivalent records in Iowa; July 1, 2025 population, 2024–2025 growth and 2025 land-area density.
Population totals use July 1, 2025 observations from PEP Vintage 2025. Change is measured since July 1, 2024. County equivalents are included, including Connecticut planning regions. Missing density is displayed as unavailable, never as zero.
Population table and filters
Whole-dataset downloads| Place | Population · 2025 | Change · 2024–25 | Growth · 2024–25 | People / sq. mi. |
|---|---|---|---|---|
| Polk CountyIowa · County equivalent · 19153 | 516,546 | +3,035 | +0.59% | 901.9 |
| Linn CountyIowa · County equivalent · 19113 | 232,028 | +1,639 | +0.71% | 323.6 |
| Scott CountyIowa · County equivalent · 19163 | 175,259 | +419 | +0.24% | 382.6 |
| Johnson CountyIowa · County equivalent · 19103 | 160,044 | +1,181 | +0.74% | 261.1 |
| Black Hawk CountyIowa · County equivalent · 19013 | 131,532 | +59 | +0.04% | 232.5 |
| Dallas CountyIowa · County equivalent · 19049 | 118,457 | +3,645 | +3.17% | 201.4 |
| Woodbury CountyIowa · County equivalent · 19193 | 106,649 | -93 | -0.09% | 122.2 |
| Story CountyIowa · County equivalent · 19169 | 101,291 | -127 | -0.13% | 176.9 |
| Dubuque CountyIowa · County equivalent · 19061 | 99,381 | +348 | +0.35% | 163.4 |
| Pottawattamie CountyIowa · County equivalent · 19155 | 92,996 | -274 | -0.29% | 97.8 |
| Warren CountyIowa · County equivalent · 19181 | 57,331 | +835 | +1.48% | 100.6 |
| Clinton CountyIowa · County equivalent · 19045 | 46,002 | +3 | +0.01% | 66.2 |
| Cerro Gordo CountyIowa · County equivalent · 19033 | 42,372 | +25 | +0.06% | 74.6 |
| Muscatine CountyIowa · County equivalent · 19139 | 41,853 | -308 | -0.73% | 95.7 |
| Marshall CountyIowa · County equivalent · 19127 | 39,890 | -238 | -0.59% | 69.7 |
| Jasper CountyIowa · County equivalent · 19099 | 38,153 | +31 | +0.08% | 52.2 |
| Des Moines CountyIowa · County equivalent · 19057 | 38,077 | -73 | -0.19% | 91.5 |
| Webster CountyIowa · County equivalent · 19187 | 36,838 | +39 | +0.11% | 51.5 |
| Sioux CountyIowa · County equivalent · 19167 | 36,774 | -3 | -0.01% | 47.9 |
| Wapello CountyIowa · County equivalent · 19179 | 35,210 | -219 | -0.62% | 81.5 |
| Marion CountyIowa · County equivalent · 19125 | 34,192 | +237 | +0.70% | 61.7 |
| Lee CountyIowa · County equivalent · 19111 | 32,306 | -174 | -0.54% | 62.4 |
| Boone CountyIowa · County equivalent · 19015 | 26,799 | +72 | +0.27% | 47.0 |
| Benton CountyIowa · County equivalent · 19011 | 26,004 | +159 | +0.62% | 36.3 |
| Plymouth CountyIowa · County equivalent · 19149 | 25,697 | +13 | +0.05% | 29.8 |
| Bremer CountyIowa · County equivalent · 19017 | 25,296 | -67 | -0.26% | 58.1 |
| Washington CountyIowa · County equivalent · 19183 | 22,667 | +65 | +0.29% | 39.8 |
| Mahaska CountyIowa · County equivalent · 19123 | 21,880 | -32 | -0.15% | 38.3 |
| Jones CountyIowa · County equivalent · 19105 | 21,253 | +82 | +0.39% | 36.9 |
| Buchanan CountyIowa · County equivalent · 19019 | 20,883 | +172 | +0.83% | 36.6 |
| Buena Vista CountyIowa · County equivalent · 19021 | 20,449 | -206 | -1.00% | 35.6 |
| Carroll CountyIowa · County equivalent · 19027 | 20,303 | -143 | -0.70% | 35.7 |
| Winneshiek CountyIowa · County equivalent · 19191 | 19,733 | +60 | +0.30% | 28.6 |
| Henry CountyIowa · County equivalent · 19087 | 19,349 | -19 | -0.10% | 44.6 |
| Jackson CountyIowa · County equivalent · 19097 | 19,288 | -63 | -0.33% | 30.3 |
| Fayette CountyIowa · County equivalent · 19065 | 19,047 | -63 | -0.33% | 26.1 |
| Poweshiek CountyIowa · County equivalent · 19157 | 18,368 | -55 | -0.30% | 31.4 |
| Cedar CountyIowa · County equivalent · 19031 | 18,359 | +71 | +0.39% | 31.7 |
| Dickinson CountyIowa · County equivalent · 19059 | 18,077 | +5 | +0.03% | 47.5 |
| Delaware CountyIowa · County equivalent · 19055 | 17,674 | +72 | +0.41% | 30.6 |
| Madison CountyIowa · County equivalent · 19121 | 17,270 | +121 | +0.71% | 30.8 |
| Clayton CountyIowa · County equivalent · 19043 | 16,845 | -138 | -0.81% | 21.6 |
| Tama CountyIowa · County equivalent · 19171 | 16,796 | -8 | -0.05% | 23.3 |
| Iowa CountyIowa · County equivalent · 19095 | 16,504 | +30 | +0.18% | 28.1 |
| Hardin CountyIowa · County equivalent · 19083 | 16,455 | -5 | -0.03% | 28.9 |
| Crawford CountyIowa · County equivalent · 19047 | 16,237 | -52 | -0.32% | 22.7 |
| Clay CountyIowa · County equivalent · 19041 | 16,202 | -319 | -1.93% | 28.6 |
| Jefferson CountyIowa · County equivalent · 19101 | 15,291 | -114 | -0.74% | 35.1 |
| Hamilton CountyIowa · County equivalent · 19079 | 14,944 | -54 | -0.36% | 25.9 |
| Floyd CountyIowa · County equivalent · 19067 | 14,901 | -180 | -1.19% | 29.8 |
Use these comparisons consistently
A larger population does not necessarily mean faster growth. Absolute change measures the number of residents gained or lost; percentage change divides that difference by the starting population. The percentage column here covers one July-to-July interval, rather than a decade or a partial calendar year. Percent growth is suppressed where the starting population is zero.
Density divides the unrounded July 1, 2025 population by matching 2025 Gazetteer land area. It is measured in people per square mile and excludes water area. These geographic averages depend on the size and definition of each unit, so a county’s density is not directly comparable to a built-up city neighborhood.
County-equivalent names and units vary by state. Connecticut planning regions are represented in the current series; linking older county series requires a documented relationship. Incorporated places may cross county boundaries and do not form an exhaustive county breakdown.
Exports contain the current page’s visible rows after filtering, with reference date and release metadata. Use whole-dataset downloads for every row or select a compatible comparison to inspect a longer interval. The initial pep-2025-r1 snapshot remains reproducible when future releases are added.