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What are the fastest-growing counties in Iowa?

Dallas County (+17.8%), Warren County (+9.0%) and Polk County (+4.8%) grew fastest in Iowa between 2020 and 2025.

Iowa as a whole grew 1.5% between 2020 and 2025, to 3,238,387 residents.

Data as of 2025 · updated

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All 99 Iowa counties ranked

Iowa counties by population growth
RankCountyResidents 2025Change 2020–25Net migration per 1,000, 2025New homes per 1,000, 2025
1Dallas County118,457+17.8%21.47.4
2Warren County57,331+9.0%12.68.1
3Polk County516,546+4.8%−1.29.2
4Johnson County160,044+4.6%−1.17.8
5Madison County17,270+3.8%6.83.8
6Lyon County12,354+3.6%−4.13.3
7Wayne County6,738+3.6%12.50.4
8Jones County21,253+2.9%4.20.8
9Story County101,291+2.7%−7.81.8
10Mills County14,793+2.6%4.31.7
11Lucas County8,847+2.6%−1.10.2
12Sioux County36,774+2.5%−6.19.8
13Marion County34,192+2.3%7.99.9
14Benton County26,004+1.8%5.01.1
15Dickinson County18,077+1.7%6.06.5
16Guthrie County10,782+1.6%12.33.1
17Buchanan County20,883+1.3%5.63.0
18Davis County9,230+1.3%−3.40.1
19Delaware County17,674+1.2%4.91.9
20Allamakee County14,238+1.2%0.66.9
21Bremer County25,296+1.1%−2.61.8
22Jasper County38,153+0.9%−2.52.1
23Linn County232,028+0.7%2.74.1
24Woodbury County106,649+0.7%−6.92.2
25Washington County22,667+0.6%1.91.1
26Mitchell County10,650+0.6%6.43.5
27O'Brien County14,220+0.5%0.61.3
28Harrison County14,623+0.4%4.71.4
29Scott County175,259+0.4%−0.12.1
30Black Hawk County131,532+0.4%−4.03.7
31Boone County26,799+0.4%5.57.7
32Grundy County12,361+0.2%−1.51.6
33Dubuque County99,381+0.1%1.83.4
34Ringgold County4,642+0.0%3.01.3
35Plymouth County25,697+0.0%0.31.8
36Shelby County11,689−0.2%−3.50.3
37Wapello County35,210−0.4%−10.81.2
38Webster County36,838−0.4%−0.30.6
39Taylor County5,835−0.5%1.20.7
40Hamilton County14,944−0.5%−6.40.8
41Marshall County39,890−0.5%−8.20.8
42Cedar County18,359−0.7%4.73.6
43Pottawattamie County92,996−0.7%−0.23.6
44Fremont County6,522−0.8%8.12.3
45Jackson County19,288−0.8%−1.91.7
46Howard County9,415−0.8%−4.10.6
47Clay County16,202−0.9%−18.03.8
48Wright County12,801−0.9%−7.71.5
49Clinton County46,002−0.9%2.41.8
50Decatur County7,655−0.9%−3.10.1
51Iowa County16,504−1.0%2.00.5
52Palo Alto County8,899−1.0%1.70.7
53Greene County8,658−1.0%5.10.7
54Clayton County16,845−1.1%−5.93.3
55Cass County12,960−1.2%3.00.8
56Mahaska County21,880−1.2%−1.33.0
57Franklin County9,868−1.2%−10.40.3
58Van Buren County7,131−1.2%−7.00.7
59Adair County7,403−1.3%−6.23.1
60Worth County7,338−1.3%5.30.7
61Poweshiek County18,368−1.4%−2.02.4
62Tama County16,796−1.5%−1.80.3
63Cerro Gordo County42,372−1.5%3.62.7
64Crawford County16,237−1.5%−6.91.2
65Winneshiek County19,733−1.6%1.81.8
66Clarke County9,574−1.6%−2.714.4
67Appanoose County12,077−1.7%1.90.9
68Buena Vista County20,449−1.7%−19.30.8
69Humboldt County9,409−2.0%−9.11.5
70Des Moines County38,077−2.0%0.72.1
71Butler County14,049−2.0%−0.71.3
72Keokuk County9,797−2.0%3.20.1
73Carroll County20,303−2.0%−6.21.8
74Fayette County19,047−2.1%−1.61.6
75Hancock County10,528−2.2%−7.90.7
76Hardin County16,455−2.2%3.11.1
77Page County14,856−2.3%−4.70.8
78Monona County8,539−2.4%7.50.8
79Cherokee County11,369−2.4%−7.24.9
80Union County11,829−2.5%−4.71.9
81Emmet County9,107−2.5%−0.11.5
82Adams County3,617−2.5%7.73.3
83Jefferson County15,291−2.5%−16.70.1
84Monroe County7,406−2.6%8.41.6
85Sac County9,525−2.7%−9.31.5
86Chickasaw County11,663−2.8%−5.40.7
87Muscatine County41,853−3.0%−7.72.8
88Audubon County5,509−3.0%−2.21.3
89Kossuth County14,322−3.2%−9.30.3
90Montgomery County10,002−3.2%2.22.9
91Calhoun County9,562−3.4%−2.51.4
92Ida County6,777−3.4%4.90.3
93Pocahontas County6,819−3.6%−10.90.0
94Osceola County5,980−3.6%−2.70.5
95Lee County32,306−3.6%−3.02.5
96Louisa County10,416−3.8%−13.02.0
97Winnebago County10,251−3.8%−3.40.4
98Floyd County14,901−4.5%−9.35.2
99Henry County19,349−5.4%2.51.7

Ranked by the change in Census Bureau population estimates, 2020–2025.

Statewide totals

More county rankings for Iowa

Metro areas

Fastest-growing metro areas in Iowa · Fastest-growing metro areas in the U.S. · Largest metro areas in Iowa

Every U.S. metro and micro area

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Questions

Is Iowa growing?

Iowa as a whole grew 1.5% between 2020 and 2025, to 3,238,387 residents. Statewide figures add up its counties.

What is the fastest-growing county in Iowa?

Dallas County, which grew 17.8% between 2020 and 2025 to 118,457 residents (Census Bureau population estimates). Warren County (+9.0%) and Polk County (+4.8%) came next.

Which Iowa counties are losing population?

64 of the 99 ranked counties had fewer residents in 2025 than in 2020. The steepest declines: Henry County (−5.4%), Floyd County (−4.5%), Winnebago County (−3.8%).

Where are people moving in Iowa?

For their size, Dallas County (21.4 per 1,000 residents), Warren County (12.6 per 1,000 residents) and Wayne County (12.5 per 1,000 residents) drew the most net domestic migration (people moving in from other U.S. counties minus people moving out) in 2025.

Fastest-growing counties in other states

Across the U.S.

Sources and method

Each number shows its own period. Changes compare the latest period with five years earlier (or the earliest period available). Beacon CRE last refreshed these figures on 2026-11-05. Figures come from public federal statistics and are informational only, not investment advice. Check the source before relying on a number. Methodology: how we compute every number. More on every layer: data sources and licences.