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

Dickinson County had the highest median age on 1 July (US county estimates) of 99 counties in 2019, at 49.1 years. Story County had the lowest, at 26.7 years. The median was 42.6 years. Source: the U.S. Census Bureau.

Keep it in a collection in your library.
Highest49.1Dickinson County
Lowest26.7Story County
Median42.699 counties

Map of counties, 2019

Adair County: 44.1 yearsAdams County: 47.1 yearsAllamakee County: 43.9 yearsAppanoose County: 45.1 yearsAudubon County: 47.5 yearsBenton County: 42.3 yearsBlack Hawk County: 36.5 yearsBoone County: 41.8 yearsBremer County: 39.7 yearsBuchanan County: 39.6 yearsBuena Vista County: 35.9 yearsButler County: 45.3 yearsCalhoun County: 44.3 yearsCarroll County: 42.4 yearsCass County: 45.6 yearsCedar County: 43.2 yearsCerro Gordo County: 44.7 yearsCherokee County: 46.4 yearsChickasaw County: 43.9 yearsClarke County: 40.3 yearsClay County: 42.5 yearsClayton County: 46.7 yearsClinton County: 42.5 yearsCrawford County: 37.8 yearsDallas County: 35.2 yearsDavis County: 36.1 yearsDecatur County: 39.2 yearsDelaware County: 43.5 yearsDes Moines County: 42.8 yearsDickinson County: 49.1 yearsDubuque County: 38.8 yearsEmmet County: 42.7 yearsFayette County: 43.6 yearsFloyd County: 43.9 yearsFranklin County: 42.6 yearsFremont County: 45.9 yearsGreene County: 44.8 yearsGrundy County: 42.9 yearsGuthrie County: 46.6 yearsHamilton County: 42.9 yearsHancock County: 45.1 yearsHardin County: 43.3 yearsHarrison County: 43.8 yearsHenry County: 40.8 yearsHoward County: 41.9 yearsHumboldt County: 42.3 yearsIda County: 44 yearsIowa County: 42.6 yearsJackson County: 44.9 yearsJasper County: 42.1 yearsJefferson County: 46.2 yearsJohnson County: 31 yearsJones County: 43.4 yearsKeokuk County: 43.1 yearsKossuth County: 46.5 yearsLee County: 44.5 yearsLinn County: 37.8 yearsLouisa County: 42.2 yearsLucas County: 43.8 yearsLyon County: 37.6 yearsMadison County: 41.6 yearsMahaska County: 39.5 yearsMarion County: 40.8 yearsMarshall County: 39.2 yearsMills County: 42.6 yearsMitchell County: 43.9 yearsMonona County: 46.2 yearsMonroe County: 43.1 yearsMontgomery County: 45.1 yearsMuscatine County: 39.2 yearsO'Brien County: 42 yearsOsceola County: 43.7 yearsPage County: 43 yearsPalo Alto County: 43.6 yearsPlymouth County: 40.5 yearsPocahontas County: 45.5 yearsPolk County: 35.8 yearsPottawattamie County: 39.8 yearsPoweshiek County: 40.8 yearsRinggold County: 45.7 yearsSac County: 46.2 yearsScott County: 38.7 yearsShelby County: 46.7 yearsSioux County: 33.4 yearsStory County: 26.7 yearsTama County: 42 yearsTaylor County: 43.4 yearsUnion County: 40.9 yearsVan Buren County: 44.3 yearsWapello County: 39.1 yearsWarren County: 38.8 yearsWashington County: 41.2 yearsWayne County: 40.5 yearsWebster County: 40 yearsWinnebago County: 42.3 yearsWinneshiek County: 42.6 yearsWoodbury County: 35.7 yearsWorth County: 43.8 yearsWright County: 41.1 years
  • Under 39
  • 39 to 41
  • 41 to 43
  • 43 to 44
  • 44 to 45
  • 45 and over
years, 2019. 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, 2019

Dickinson County: 49.1 yearsDickinson County49.1Audubon County: 47.5 yearsAudubon County47.5Adams County: 47.1 yearsAdams County47.1Clayton County: 46.7 yearsClayton County46.7Shelby County: 46.7 yearsShelby County46.7Guthrie County: 46.6 yearsGuthrie County46.6Kossuth County: 46.5 yearsKossuth County46.5Cherokee County: 46.4 yearsCherokee County46.4Jefferson County: 46.2 yearsJefferson County46.2Monona County: 46.2 yearsMonona County46.2Sac County: 46.2 yearsSac County46.2Fremont County: 45.9 yearsFremont County45.9Ringgold County: 45.7 yearsRinggold County45.7Cass County: 45.6 yearsCass County45.6Pocahontas County: 45.5 yearsPocahontas County45.5Butler County: 45.3 yearsButler County45.3Appanoose County: 45.1 yearsAppanoose County45.1Hancock County: 45.1 yearsHancock County45.1Montgomery County: 45.1 yearsMontgomery County45.1Jackson County: 44.9 yearsJackson County44.9Greene County: 44.8 yearsGreene County44.8Cerro Gordo County: 44.7 yearsCerro Gordo County44.7Lee County: 44.5 yearsLee County44.5Calhoun County: 44.3 yearsCalhoun County44.3Van Buren County: 44.3 yearsVan Buren County44.3Adair County: 44.1 yearsAdair County44.1Ida County: 44 yearsIda County44Allamakee County: 43.9 yearsAllamakee County43.9Chickasaw County: 43.9 yearsChickasaw County43.9Floyd County: 43.9 yearsFloyd County43.9Mitchell County: 43.9 yearsMitchell County43.9Harrison County: 43.8 yearsHarrison County43.8Lucas County: 43.8 yearsLucas County43.8Worth County: 43.8 yearsWorth County43.8Osceola County: 43.7 yearsOsceola County43.7Fayette County: 43.6 yearsFayette County43.6Palo Alto County: 43.6 yearsPalo Alto County43.6Delaware County: 43.5 yearsDelaware County43.5Jones County: 43.4 yearsJones County43.4Taylor County: 43.4 yearsTaylor County43.4Dickinson County: 49.1 yearsDickinson County49.1Audubon County: 47.5 yearsAudubon County47.5Adams County: 47.1 yearsAdams County47.1Clayton County: 46.7 yearsClayton County46.7Shelby County: 46.7 yearsShelby County46.7Guthrie County: 46.6 yearsGuthrie County46.6Kossuth County: 46.5 yearsKossuth County46.5Cherokee County: 46.4 yearsCherokee County46.4Jefferson County: 46.2 yearsJefferson County46.2Monona County: 46.2 yearsMonona County46.2Sac County: 46.2 yearsSac County46.2Fremont County: 45.9 yearsFremont County45.9Ringgold County: 45.7 yearsRinggold County45.7Cass County: 45.6 yearsCass County45.6Pocahontas County: 45.5 yearsPocahontas County45.5Butler County: 45.3 yearsButler County45.3Appanoose County: 45.1 yearsAppanoose County45.1Hancock County: 45.1 yearsHancock County45.1Montgomery County: 45.1 yearsMontgomery County45.1Jackson County: 44.9 yearsJackson County44.9Greene County: 44.8 yearsGreene County44.8Cerro Gordo County: 44.7 yearsCerro Gordo County44.7Lee County: 44.5 yearsLee County44.5Calhoun County: 44.3 yearsCalhoun County44.3Van Buren County: 44.3 yearsVan Buren County44.3Adair County: 44.1 yearsAdair County44.1Ida County: 44 yearsIda County44Allamakee County: 43.9 yearsAllamakee County43.9Chickasaw County: 43.9 yearsChickasaw County43.9Floyd County: 43.9 yearsFloyd County43.9Mitchell County: 43.9 yearsMitchell County43.9Harrison County: 43.8 yearsHarrison County43.8Lucas County: 43.8 yearsLucas County43.8Worth County: 43.8 yearsWorth County43.8Osceola County: 43.7 yearsOsceola County43.7Fayette County: 43.6 yearsFayette County43.6Palo Alto County: 43.6 yearsPalo Alto County43.6Delaware County: 43.5 yearsDelaware County43.5Jones County: 43.4 yearsJones 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

RankCounties2019
years
Change on 2018
1Dickinson County49.1+0.1
2Audubon County47.5-0.8
3Adams County47.1+0.7
4Clayton County46.70
4Shelby County46.7+0.2
6Guthrie County46.6+0.6
7Kossuth County46.5-0.2
8Cherokee County46.4-0.2
9Jefferson County46.2+0.7
9Monona County46.2-0.1
9Sac County46.2-0.7
12Fremont County45.9+0.3
13Ringgold County45.7+0.2
14Cass County45.6+0.1
15Pocahontas County45.5+0.5
16Butler County45.3+0.2
17Appanoose County45.1-0.3
17Hancock County45.1-0.3
17Montgomery County45.10
20Jackson County44.90
21Greene County44.8+0.1
22Cerro Gordo County44.70
23Lee County44.5+0.3
24Calhoun County44.30
24Van Buren County44.3-0.5
26Adair County44.1-0.7
27Ida County44-0.3
28Allamakee County43.9+0.2
28Chickasaw County43.9-0.1
28Floyd County43.9+0.3
28Mitchell County43.9+0.1
32Harrison County43.8+0.1
32Lucas County43.8+0.4
32Worth County43.8-0.3
35Osceola County43.70
36Fayette County43.60
36Palo Alto County43.6-0.2
38Delaware County43.5+0.2
39Jones County43.4+0.2
39Taylor County43.40
41Hardin County43.30
42Cedar County43.20
43Keokuk County43.1-0.5
43Monroe County43.1+0.5
45Page County430
46Grundy County42.9+0.2
46Hamilton County42.90
48Des Moines County42.80
49Emmet County42.7+0.4
50Franklin County42.6-0.1
50Iowa County42.6-0.1
50Mills County42.6+0.2
50Winneshiek County42.6+0.2
54Clay County42.50
54Clinton County42.5-0.2
56Carroll County42.4+0.3
57Benton County42.3+0.1
57Humboldt County42.3-0.3
57Winnebago County42.3+0.3
60Louisa County42.2+0.6
61Jasper County42.1+0.2
62O'Brien County420
62Tama County42-0.2
64Howard County41.9-0.1
65Boone County41.8+0.2
66Madison County41.60
67Washington County41.2+0.2
68Wright County41.1-0.5
69Union County40.9-0.2
70Henry County40.8+0.4
70Marion County40.8+0.4
70Poweshiek County40.8-0.1
73Plymouth County40.5-0.2
73Wayne County40.5-0.6
75Clarke County40.3+0.8
76Webster County40+0.1
77Pottawattamie County39.8+0.2
78Bremer County39.7+0.2
79Buchanan County39.6+0.3
80Mahaska County39.5-0.3
81Decatur County39.2+0.6
81Marshall County39.2+0.3
81Muscatine County39.2+0.4
84Wapello County39.1-0.1
85Dubuque County38.8+0.1
85Warren County38.8+0.3
87Scott County38.7+0.3
88Crawford County37.8-0.1
88Linn County37.8+0.2
90Lyon County37.6+0.4
91Black Hawk County36.5+0.4
92Davis County36.1-0.5
93Buena Vista County35.9+0.1
94Polk County35.8+0.2
95Woodbury County35.70
96Dallas County35.2+0.1
97Sioux County33.40
98Johnson County31+0.2
99Story County26.7+0.2

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), 2019) [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), 2019. 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=2019. 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), 2019. 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=2019.

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), 2019 [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=2019 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_iowa_by_2019,
  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), 2019}},
  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=2019. 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), 2019
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=2019
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/iowa-counties?period=2019.
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)?

Dickinson County, with 49.1 years in 2019, according to the U.S. Census Bureau.

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

Story County, with 26.7 years in 2019.

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