Data / Rankings / Median age / Counties in Iowa

Counties in Iowa by median age

Audubon County had the highest median age of 99 counties in 2021, at 48.1 years. Story County had the lowest, at 26.9 years. The median was 42.1 years and the figure for Iowa was 38.3 years. Source: the U.S. Census Bureau.

Highest48.1Audubon County
Lowest26.9Story County
Median42.199 counties
Iowa38.3History

Top 40 counties, 2021

CSVChart (SVG)

Audubon CountyAudubon County: 48.1 years48.1Dickinson CountyDickinson County: 47.8 years47.8Clayton CountyClayton County: 47.1 years47.1Adams CountyAdams County: 46.7 years46.7Monona CountyMonona County: 46.3 years46.3Fremont CountyFremont County: 46.1 years46.1Sac CountySac County: 46.1 years46.1Guthrie CountyGuthrie County: 45.7 years45.7Pocahontas CountyPocahontas County: 45.4 years45.4Shelby CountyShelby County: 45.3 years45.3Van Buren CountyVan Buren County: 45 years45Appanoose CountyAppanoose County: 44.9 years44.9Cherokee CountyCherokee County: 44.8 years44.8Hardin CountyHardin County: 44.7 years44.7Kossuth CountyKossuth County: 44.7 years44.7Page CountyPage County: 44.4 years44.4Greene CountyGreene County: 44.3 years44.3Ringgold CountyRinggold County: 44.3 years44.3Cass CountyCass County: 44.2 years44.2Cerro Gordo CountyCerro Gordo County: 44.2 years44.2Hancock CountyHancock County: 44.2 years44.2Jackson CountyJackson County: 44.1 years44.1Lucas CountyLucas County: 44 years44Osceola CountyOsceola County: 43.8 years43.8Delaware CountyDelaware County: 43.7 years43.7Floyd CountyFloyd County: 43.6 years43.6Taylor CountyTaylor County: 43.6 years43.6Allamakee CountyAllamakee County: 43.5 years43.5Butler CountyButler County: 43.5 years43.5Calhoun CountyCalhoun County: 43.5 years43.5Adair CountyAdair County: 43.4 years43.4Chickasaw CountyChickasaw County: 43.4 years43.4Worth CountyWorth County: 43.4 years43.4Franklin CountyFranklin County: 43.3 years43.3Lee CountyLee County: 43.2 years43.2Benton CountyBenton County: 43.1 years43.1Emmet CountyEmmet County: 43 years43Fayette CountyFayette County: 43 years43Iowa CountyIowa County: 42.9 years42.9Keokuk CountyKeokuk County: 42.9 years42.9
years. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2021
years
1Audubon County48.1
2Dickinson County47.8
3Clayton County47.1
4Adams County46.7
5Monona County46.3
6Fremont County46.1
6Sac County46.1
8Guthrie County45.7
9Pocahontas County45.4
10Shelby County45.3
11Van Buren County45
12Appanoose County44.9
13Cherokee County44.8
14Hardin County44.7
14Kossuth County44.7
16Page County44.4
17Greene County44.3
17Ringgold County44.3
19Cass County44.2
19Cerro Gordo County44.2
19Hancock County44.2
22Jackson County44.1
23Lucas County44
24Osceola County43.8
25Delaware County43.7
26Floyd County43.6
26Taylor County43.6
28Allamakee County43.5
28Butler County43.5
28Calhoun County43.5
31Adair County43.4
31Chickasaw County43.4
31Worth County43.4
34Franklin County43.3
35Lee County43.2
36Benton County43.1
37Emmet County43
37Fayette County43
39Iowa County42.9
39Keokuk County42.9
41Des Moines County42.7
41Jones County42.7
43Cedar County42.6
43Montgomery County42.6
45Clinton County42.5
46Harrison County42.4
46Mills County42.4
48Wright County42.3
49Boone County42.2
50Humboldt County42.1
51Carroll County42
51Grundy County42
51Hamilton County42
54Palo Alto County41.9
55Ida County41.8
55Louisa County41.8
55Mitchell County41.8
55Tama County41.8
59Winneshiek County41.7
60Jefferson County41.6
60Monroe County41.6
60Wayne County41.6
63Winnebago County41.4
64Clay County41
65Jasper County40.9
66O'Brien County40.7
66Poweshiek County40.7
68Henry County40.6
69Howard County40.5
69Madison County40.5
71Plymouth County40.4
72Washington County40.2
73Union County39.7
74Marion County39.6
75Pottawattamie County39.5
76Buchanan County39.2
76Wapello County39.2
76Webster County39.2
79Bremer County39
80Scott County38.7
81Dubuque County38.6
81Mahaska County38.6
83Marshall County38.4
83Warren County38.4
85Muscatine County38.3
86Clarke County38.2
87Linn County37.9
87Lyon County37.9
89Crawford County37.2
90Davis County36
91Decatur County35.9
91Polk County35.9
93Woodbury County35.8
94Black Hawk County35.6
95Dallas County35.5
96Buena Vista County35.2
97Sioux County33.8
98Johnson County30.7
99Story County26.9

Other periods

About this ranking

Age that divides the resident population into two halves of equal size. Spain and the EU: on 1 January. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. American Community Survey 5-year estimates, table B01002: median age, total population. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b01002.dat. Retrieved 2026-10-08.

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Questions

Which county has the highest median age?

Audubon County, with 48.1 years in 2021, according to the U.S. Census Bureau.

Which county has the lowest median age?

Story County, with 26.9 years in 2021.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B01002: median age, total population. Retrieved 2026-10-08.

Median age: other rankings

Counties in Iowa: more rankings