Counties in Iowa by median age on 1 July (US county estimates)

Audubon County had the highest median age on 1 July (US county estimates) of 99 counties in 2016, at 48.8 years. Story County had the lowest, at 25.8 years. The median was 42.7 years. Source: the U.S. Census Bureau.

Keep it in a collection in your library.
Highest48.8Audubon County
Lowest25.8Story County
Median42.799 counties

Map of counties, 2016

Adair County: 45.6 yearsAdams County: 46.2 yearsAllamakee County: 44.5 yearsAppanoose County: 45 yearsAudubon County: 48.8 yearsBenton County: 41.9 yearsBlack Hawk County: 35.4 yearsBoone County: 41.3 yearsBremer County: 39.6 yearsBuchanan County: 39 yearsBuena Vista County: 35.3 yearsButler County: 44.8 yearsCalhoun County: 44.7 yearsCarroll County: 42.2 yearsCass County: 44.8 yearsCedar County: 43.1 yearsCerro Gordo County: 44.4 yearsCherokee County: 47.3 yearsChickasaw County: 44 yearsClarke County: 40 yearsClay County: 42.4 yearsClayton County: 46.5 yearsClinton County: 42.5 yearsCrawford County: 37.9 yearsDallas County: 34.9 yearsDavis County: 37 yearsDecatur County: 38.1 yearsDelaware County: 43.1 yearsDes Moines County: 42.3 yearsDickinson County: 48.4 yearsDubuque County: 38.5 yearsEmmet County: 42 yearsFayette County: 44.1 yearsFloyd County: 43.8 yearsFranklin County: 43.4 yearsFremont County: 45.7 yearsGreene County: 45.3 yearsGrundy County: 42.8 yearsGuthrie County: 45.9 yearsHamilton County: 42.7 yearsHancock County: 45.4 yearsHardin County: 43.1 yearsHarrison County: 44 yearsHenry County: 40.6 yearsHoward County: 41.9 yearsHumboldt County: 43 yearsIda County: 44.7 yearsIowa County: 42.9 yearsJackson County: 45 yearsJasper County: 42.4 yearsJefferson County: 43.7 yearsJohnson County: 30.3 yearsJones County: 43.1 yearsKeokuk County: 44 yearsKossuth County: 46.6 yearsLee County: 43.9 yearsLinn County: 37.2 yearsLouisa County: 41 yearsLucas County: 44.6 yearsLyon County: 37.5 yearsMadison County: 41.4 yearsMahaska County: 39.5 yearsMarion County: 39.7 yearsMarshall County: 39.1 yearsMills County: 42.6 yearsMitchell County: 44.3 yearsMonona County: 47 yearsMonroe County: 42.6 yearsMontgomery County: 45.1 yearsMuscatine County: 38.5 yearsO'Brien County: 42.9 yearsOsceola County: 44.1 yearsPage County: 42.9 yearsPalo Alto County: 43.6 yearsPlymouth County: 40.9 yearsPocahontas County: 46.2 yearsPolk County: 35.3 yearsPottawattamie County: 39.2 yearsPoweshiek County: 41.1 yearsRinggold County: 45.2 yearsSac County: 46.7 yearsScott County: 37.9 yearsShelby County: 46.5 yearsSioux County: 32.9 yearsStory County: 25.8 yearsTama County: 42.5 yearsTaylor County: 43.4 yearsUnion County: 41.2 yearsVan Buren County: 44.7 yearsWapello County: 39.2 yearsWarren County: 38.5 yearsWashington County: 40.9 yearsWayne County: 41.4 yearsWebster County: 39.7 yearsWinnebago County: 42.7 yearsWinneshiek County: 41.5 yearsWoodbury County: 35.4 yearsWorth County: 44.1 yearsWright County: 42.7 years
  • Under 39
  • 39 to 41
  • 41 to 43
  • 43 to 44
  • 44 to 45
  • 45 and over
years, 2016. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2016

Audubon County: 48.8 yearsAudubon County48.8Dickinson County: 48.4 yearsDickinson County48.4Cherokee County: 47.3 yearsCherokee County47.3Monona County: 47 yearsMonona County47Sac County: 46.7 yearsSac County46.7Kossuth County: 46.6 yearsKossuth County46.6Clayton County: 46.5 yearsClayton County46.5Shelby County: 46.5 yearsShelby County46.5Adams County: 46.2 yearsAdams County46.2Pocahontas County: 46.2 yearsPocahontas County46.2Guthrie County: 45.9 yearsGuthrie County45.9Fremont County: 45.7 yearsFremont County45.7Adair County: 45.6 yearsAdair County45.6Hancock County: 45.4 yearsHancock County45.4Greene County: 45.3 yearsGreene County45.3Ringgold County: 45.2 yearsRinggold County45.2Montgomery County: 45.1 yearsMontgomery County45.1Appanoose County: 45 yearsAppanoose County45Jackson County: 45 yearsJackson County45Butler County: 44.8 yearsButler County44.8Cass County: 44.8 yearsCass County44.8Calhoun County: 44.7 yearsCalhoun County44.7Ida County: 44.7 yearsIda County44.7Van Buren County: 44.7 yearsVan Buren County44.7Lucas County: 44.6 yearsLucas County44.6Allamakee County: 44.5 yearsAllamakee County44.5Cerro Gordo County: 44.4 yearsCerro Gordo County44.4Mitchell County: 44.3 yearsMitchell County44.3Fayette County: 44.1 yearsFayette County44.1Osceola County: 44.1 yearsOsceola County44.1Worth County: 44.1 yearsWorth County44.1Chickasaw County: 44 yearsChickasaw County44Harrison County: 44 yearsHarrison County44Keokuk County: 44 yearsKeokuk County44Lee County: 43.9 yearsLee County43.9Floyd County: 43.8 yearsFloyd County43.8Jefferson County: 43.7 yearsJefferson County43.7Palo Alto County: 43.6 yearsPalo Alto County43.6Franklin County: 43.4 yearsFranklin County43.4Taylor County: 43.4 yearsTaylor County43.4Audubon County: 48.8 yearsAudubon County48.8Dickinson County: 48.4 yearsDickinson County48.4Cherokee County: 47.3 yearsCherokee County47.3Monona County: 47 yearsMonona County47Sac County: 46.7 yearsSac County46.7Kossuth County: 46.6 yearsKossuth County46.6Clayton County: 46.5 yearsClayton County46.5Shelby County: 46.5 yearsShelby County46.5Adams County: 46.2 yearsAdams County46.2Pocahontas County: 46.2 yearsPocahontas County46.2Guthrie County: 45.9 yearsGuthrie County45.9Fremont County: 45.7 yearsFremont County45.7Adair County: 45.6 yearsAdair County45.6Hancock County: 45.4 yearsHancock County45.4Greene County: 45.3 yearsGreene County45.3Ringgold County: 45.2 yearsRinggold County45.2Montgomery County: 45.1 yearsMontgomery County45.1Appanoose County: 45 yearsAppanoose County45Jackson County: 45 yearsJackson County45Butler County: 44.8 yearsButler County44.8Cass County: 44.8 yearsCass County44.8Calhoun County: 44.7 yearsCalhoun County44.7Ida County: 44.7 yearsIda County44.7Van Buren County: 44.7 yearsVan Buren County44.7Lucas County: 44.6 yearsLucas County44.6Allamakee County: 44.5 yearsAllamakee County44.5Cerro Gordo County: 44.4 yearsCerro Gordo County44.4Mitchell County: 44.3 yearsMitchell County44.3Fayette County: 44.1 yearsFayette County44.1Osceola County: 44.1 yearsOsceola County44.1Worth County: 44.1 yearsWorth County44.1Chickasaw County: 44 yearsChickasaw County44Harrison County: 44 yearsHarrison County44Keokuk County: 44 yearsKeokuk County44Lee County: 43.9 yearsLee County43.9Floyd County: 43.8 yearsFloyd County43.8Jefferson County: 43.7 yearsJefferson County43.7Palo Alto County: 43.6 yearsPalo Alto County43.6Franklin County: 43.4 yearsFranklin County43.4Taylor County: 43.4 yearsTaylor County43.4
years. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Full ranking

RankCounties2016
years
Change on 2015
1Audubon County48.80
2Dickinson County48.4-0.1
3Cherokee County47.3-0.2
4Monona County47-0.3
5Sac County46.7+0.3
6Kossuth County46.6-0.3
7Clayton County46.5+0.3
7Shelby County46.5+0.1
9Adams County46.2+0.2
9Pocahontas County46.20
11Guthrie County45.9+0.2
12Fremont County45.7-0.3
13Adair County45.6-0.3
14Hancock County45.4+0.5
15Greene County45.30
16Ringgold County45.20
17Montgomery County45.10
18Appanoose County450
18Jackson County45+0.1
20Butler County44.8+0.5
20Cass County44.80
22Calhoun County44.7-0.8
22Ida County44.7+0.2
22Van Buren County44.70
25Lucas County44.6-0.1
26Allamakee County44.5-0.3
27Cerro Gordo County44.4-0.3
28Mitchell County44.30
29Fayette County44.1+0.2
29Osceola County44.1+0.3
29Worth County44.1-0.2
32Chickasaw County440
32Harrison County440
32Keokuk County44-0.1
35Lee County43.9+0.5
36Floyd County43.80
37Jefferson County43.7+0.3
38Palo Alto County43.6+0.1
39Franklin County43.4+0.3
39Taylor County43.4+0.2
41Cedar County43.1-0.2
41Delaware County43.1+0.3
41Hardin County43.1-0.4
41Jones County43.1-0.1
45Humboldt County43-0.6
46Iowa County42.9+0.2
46O'Brien County42.9-0.6
46Page County42.9-0.1
49Grundy County42.8-0.1
50Hamilton County42.70
50Winnebago County42.7-0.5
50Wright County42.7-0.6
53Mills County42.6-0.1
53Monroe County42.6+0.1
55Clinton County42.5+0.1
55Tama County42.5-0.3
57Clay County42.4-0.1
57Jasper County42.4+0.1
59Des Moines County42.3+0.1
60Carroll County42.2-0.2
61Emmet County42+0.3
62Benton County41.90
62Howard County41.9+0.2
64Winneshiek County41.5+0.9
65Madison County41.4+0.1
65Wayne County41.4-1.4
67Boone County41.3+0.1
68Union County41.20
69Poweshiek County41.10
70Louisa County41+0.5
71Plymouth County40.9-0.4
71Washington County40.90
73Henry County40.6-0.1
74Clarke County40-0.6
75Marion County39.7+0.1
75Webster County39.7-0.1
77Bremer County39.60
78Mahaska County39.5+0.2
79Pottawattamie County39.2+0.1
79Wapello County39.2-0.2
81Marshall County39.10
82Buchanan County39+0.3
83Dubuque County38.5+0.1
83Muscatine County38.50
83Warren County38.5-0.3
86Decatur County38.1+1.1
87Crawford County37.9-0.2
87Scott County37.9+0.2
89Lyon County37.50
90Linn County37.20
91Davis County37-0.5
92Black Hawk County35.4+0.4
92Woodbury County35.4+0.1
94Buena Vista County35.3+0.1
94Polk County35.3+0.1
96Dallas County34.90
97Sioux County32.9+0.1
98Johnson County30.3+0.1
99Story County25.8+0.3

Other periods

About this ranking

Age that divides the resident population of a US county into two halves of equal size on 1 July, from Census Bureau population estimates calculated by single year of age.

Counties only: the county file has no state or national medians, and medians cannot be added up. A single-year estimate, unlike median_age, which for US places is a five-year American Community Survey estimate.

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. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage (Counties in Iowa by median age on 1 July (US county estimates), 2016) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Iowa by median age on 1 July (US county estimates), 2016. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Counties in Iowa by median age on 1 July (US county estimates), 2016. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Iowa by median age on 1 July (US county estimates), 2016 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_iowa_by_2016,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Iowa by median age on 1 July (US county estimates), 2016}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Iowa by median age on 1 July (US county estimates), 2016
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2016.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  - 
Embed this chart

Paste this code into a web page or a blog post. The chart shows the latest figures as they are published, with the source and a link back to this page.

Sites that read oEmbed links, such as WordPress, can show the chart when you paste the link to this page.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Iowa by median age on 1 July (US county estimates) using official data, and cite the source.
rank_places {"indicator":"median_age_pep","level":"province","within":"Iowa","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=median_age_pep&level=province&within=Iowa&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest median age on 1 July (US county estimates)?

Audubon County, with 48.8 years in 2016, according to the U.S. Census Bureau.

Which county has the lowest median age on 1 July (US county estimates)?

Story County, with 25.8 years in 2016.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Median age on 1 July (US county estimates): other rankings

Counties in Iowa: more rankings