Data / Rankings / High school graduate or higher, population 25 and over / Counties in Iowa

Counties in Iowa by high school graduate or higher, population 25 and over

Story County had the highest high school graduate or higher, population 25 and over of 99 counties in 2021, at 96.9%. Buena Vista County had the lowest, at 79.4%. The median was 92.9% and the figure for Iowa was 92.8%. Source: the U.S. Census Bureau.

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Highest96.9Story County
Lowest79.4Buena Vista County
Median92.999 counties
Iowa92.8History

Map of counties, 2021

Adair County: 94.7 %Adams County: 94.5 %Allamakee County: 90.4 %Appanoose County: 90.9 %Audubon County: 91.8 %Benton County: 94.2 %Black Hawk County: 92.1 %Boone County: 94.2 %Bremer County: 96.5 %Buchanan County: 93.8 %Buena Vista County: 79.4 %Butler County: 94.1 %Calhoun County: 94 %Carroll County: 94.2 %Cass County: 89.3 %Cedar County: 95.6 %Cerro Gordo County: 93.5 %Cherokee County: 93.5 %Chickasaw County: 93.3 %Clarke County: 84.5 %Clay County: 95.5 %Clayton County: 90.9 %Clinton County: 92 %Crawford County: 81.3 %Dallas County: 95.9 %Davis County: 79.5 %Decatur County: 89.9 %Delaware County: 92.2 %Des Moines County: 92.9 %Dickinson County: 95.6 %Dubuque County: 93.8 %Emmet County: 89.8 %Fayette County: 92.6 %Floyd County: 92.8 %Franklin County: 90.8 %Fremont County: 94.7 %Greene County: 93.2 %Grundy County: 95.4 %Guthrie County: 94.4 %Hamilton County: 93.5 %Hancock County: 91.8 %Hardin County: 92.4 %Harrison County: 92.2 %Henry County: 91.9 %Howard County: 91.6 %Humboldt County: 93.1 %Ida County: 92.6 %Iowa County: 94.5 %Jackson County: 93.5 %Jasper County: 94.1 %Jefferson County: 92.8 %Johnson County: 96.2 %Jones County: 94.7 %Keokuk County: 93 %Kossuth County: 93.6 %Lee County: 93.3 %Linn County: 94.9 %Louisa County: 84.5 %Lucas County: 92.8 %Lyon County: 93.7 %Madison County: 96.5 %Mahaska County: 92 %Marion County: 94 %Marshall County: 85.3 %Mills County: 95.2 %Mitchell County: 92.8 %Monona County: 92.8 %Monroe County: 93.5 %Montgomery County: 92.2 %Muscatine County: 89.6 %O'Brien County: 91.6 %Osceola County: 88.6 %Page County: 92.1 %Palo Alto County: 93.5 %Plymouth County: 94.4 %Pocahontas County: 89.5 %Polk County: 92.5 %Pottawattamie County: 90 %Poweshiek County: 94.2 %Ringgold County: 93.3 %Sac County: 93.6 %Scott County: 93.9 %Shelby County: 93.5 %Sioux County: 92 %Story County: 96.9 %Tama County: 90.7 %Taylor County: 90.8 %Union County: 91.1 %Van Buren County: 87.8 %Wapello County: 88 %Warren County: 95.8 %Washington County: 91.9 %Wayne County: 89.5 %Webster County: 91.5 %Winnebago County: 94.3 %Winneshiek County: 95.9 %Woodbury County: 87.7 %Worth County: 93.1 %Wright County: 92.7 %
  • Under 90
  • 90 to 92
  • 92 to 93
  • 93 to 94
  • 94 to 95
  • 95 and over
%, 2021. Source: Invokely calculation with data from U.S. Census Bureau. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2021

Story County: 96.9 %Story County96.9Bremer County: 96.5 %Bremer County96.5Madison County: 96.5 %Madison County96.5Johnson County: 96.2 %Johnson County96.2Dallas County: 95.9 %Dallas County95.9Winneshiek County: 95.9 %Winneshiek County95.9Warren County: 95.8 %Warren County95.8Cedar County: 95.6 %Cedar County95.6Dickinson County: 95.6 %Dickinson County95.6Clay County: 95.5 %Clay County95.5Grundy County: 95.4 %Grundy County95.4Mills County: 95.2 %Mills County95.2Linn County: 94.9 %Linn County94.9Fremont County: 94.7 %Fremont County94.7Adair County: 94.7 %Adair County94.7Jones County: 94.7 %Jones County94.7Iowa County: 94.5 %Iowa County94.5Adams County: 94.5 %Adams County94.5Guthrie County: 94.4 %Guthrie County94.4Plymouth County: 94.4 %Plymouth County94.4Winnebago County: 94.3 %Winnebago County94.3Benton County: 94.2 %Benton County94.2Carroll County: 94.2 %Carroll County94.2Poweshiek County: 94.2 %Poweshiek County94.2Boone County: 94.2 %Boone County94.2Butler County: 94.1 %Butler County94.1Jasper County: 94.1 %Jasper County94.1Marion County: 94 %Marion County94Calhoun County: 94 %Calhoun County94Scott County: 93.9 %Scott County93.9Buchanan County: 93.8 %Buchanan County93.8Dubuque County: 93.8 %Dubuque County93.8Lyon County: 93.7 %Lyon County93.7Sac County: 93.6 %Sac County93.6Kossuth County: 93.6 %Kossuth County93.6Cherokee County: 93.5 %Cherokee County93.5Jackson County: 93.5 %Jackson County93.5Cerro Gordo County: 93.5 %Cerro Gordo County93.5Hamilton County: 93.5 %Hamilton County93.5Monroe County: 93.5 %Monroe County93.5Story County: 96.9 %Story County96.9Bremer County: 96.5 %Bremer County96.5Madison County: 96.5 %Madison County96.5Johnson County: 96.2 %Johnson County96.2Dallas County: 95.9 %Dallas County95.9Winneshiek County: 95.9 %Winneshiek County95.9Warren County: 95.8 %Warren County95.8Cedar County: 95.6 %Cedar County95.6Dickinson County: 95.6 %Dickinson County95.6Clay County: 95.5 %Clay County95.5Grundy County: 95.4 %Grundy County95.4Mills County: 95.2 %Mills County95.2Linn County: 94.9 %Linn County94.9Fremont County: 94.7 %Fremont County94.7Adair County: 94.7 %Adair County94.7Jones County: 94.7 %Jones County94.7Iowa County: 94.5 %Iowa County94.5Adams County: 94.5 %Adams County94.5Guthrie County: 94.4 %Guthrie County94.4Plymouth County: 94.4 %Plymouth County94.4Winnebago County: 94.3 %Winnebago County94.3Benton County: 94.2 %Benton County94.2Carroll County: 94.2 %Carroll County94.2Poweshiek County: 94.2 %Poweshiek County94.2Boone County: 94.2 %Boone County94.2Butler County: 94.1 %Butler County94.1Jasper County: 94.1 %Jasper County94.1Marion County: 94 %Marion County94Calhoun County: 94 %Calhoun County94Scott County: 93.9 %Scott County93.9Buchanan County: 93.8 %Buchanan County93.8Dubuque County: 93.8 %Dubuque County93.8Lyon County: 93.7 %Lyon County93.7Sac County: 93.6 %Sac County93.6Kossuth County: 93.6 %Kossuth County93.6Cherokee County: 93.5 %Cherokee County93.5Jackson County: 93.5 %Jackson County93.5Cerro Gordo County: 93.5 %Cerro Gordo County93.5Hamilton County: 93.5 %Hamilton County93.5Monroe County: 93.5 %Monroe County93.5
%. Source: Invokely calculation with data from U.S. Census Bureau. Retrieved 2026-10-12.

Full ranking

RankCounties2021 (%)
1Story County96.9
2Bremer County96.5
3Madison County96.5
4Johnson County96.2
5Dallas County95.9
6Winneshiek County95.9
7Warren County95.8
8Cedar County95.6
8Dickinson County95.6
10Clay County95.5
11Grundy County95.4
12Mills County95.2
13Linn County94.9
14Fremont County94.7
15Adair County94.7
16Jones County94.7
17Iowa County94.5
18Adams County94.5
19Guthrie County94.4
19Plymouth County94.4
21Winnebago County94.3
22Benton County94.2
23Carroll County94.2
24Poweshiek County94.2
25Boone County94.2
26Butler County94.1
26Jasper County94.1
28Marion County94
29Calhoun County94
30Scott County93.9
31Buchanan County93.8
32Dubuque County93.8
33Lyon County93.7
34Sac County93.6
35Kossuth County93.6
36Cherokee County93.5
36Jackson County93.5
38Cerro Gordo County93.5
39Hamilton County93.5
39Monroe County93.5
41Shelby County93.5
42Palo Alto County93.5
43Chickasaw County93.3
44Lee County93.3
45Ringgold County93.3
46Greene County93.2
47Worth County93.1
48Humboldt County93.1
49Keokuk County93
50Des Moines County92.9
51Lucas County92.8
52Floyd County92.8
52Monona County92.8
54Jefferson County92.8
55Mitchell County92.8
56Wright County92.7
57Ida County92.6
58Fayette County92.6
59Polk County92.5
60Hardin County92.4
61Delaware County92.2
61Harrison County92.2
61Montgomery County92.2
64Black Hawk County92.1
65Page County92.1
66Sioux County92
67Clinton County92
68Mahaska County92
69Washington County91.9
70Henry County91.9
71Audubon County91.8
72Hancock County91.8
73O'Brien County91.6
74Howard County91.6
75Webster County91.5
76Union County91.1
77Clayton County90.9
78Appanoose County90.9
79Franklin County90.8
79Taylor County90.8
81Tama County90.7
82Allamakee County90.4
83Pottawattamie County90
84Decatur County89.9
85Emmet County89.8
86Muscatine County89.6
87Pocahontas County89.5
88Wayne County89.5
89Cass County89.3
90Osceola County88.6
91Wapello County88
92Van Buren County87.8
93Woodbury County87.7
94Marshall County85.3
95Louisa County84.5
96Clarke County84.5
97Crawford County81.3
98Davis County79.5
99Buena Vista County79.4

Other periods

About this ranking

People aged 25 and over who hold a regular high school diploma, a GED or alternative credential, or any higher level of education, as a percentage of all people aged 25 and over. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Measures the adult population, not students: it is not the high school graduation rate of a class. Not comparable with the EU share below upper secondary education, which covers ages 25 to 64.

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 B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. 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). American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs (Counties in Iowa by high school graduate or higher, population 25 and over, 2021) [Data set]. Retrieved October 12, 2026, from https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat

MLA 9

American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs, Counties in Iowa by high school graduate or higher, population 25 and over, 2021. U.S. Census Bureau, 29 Jan. 2026, https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. Counties in Iowa by high school graduate or higher, population 25 and over, 2021. Dataset. Accessed October 12, 2026. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Also distributed by Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021.

Harvard

U.S. Census Bureau (2026) American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs, Counties in Iowa by high school graduate or higher, population 25 and over, 2021 [Dataset]. Available at: https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat, via Invokely: https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_iowa_by_2021,
  author = {{U.S. Census Bureau}},
  title = {{American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs: Counties in Iowa by high school graduate or higher, population 25 and over, 2021}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021. Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary\_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Retrieved 2026-10-12.},
}
RIS
TY  - DATA
AU  - U.S. Census Bureau
TI  - American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs: Counties in Iowa by high school graduate or higher, population 25 and over, 2021
PY  - 2026
DA  - 2026/01/29
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat
L2  - https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/high-school-graduate-or-higher/iowa-counties?period=2021.
N1  - Publisher attribution: U.S. Census Bureau. American Community Survey 5-year estimates, table B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. https://www2.census.gov/programs-surveys/acs/summary_file/2021/table-based-SF/data/5YRData/acsdt5y2021-b15003.dat. Retrieved 2026-10-12.
ER  -
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Rank Counties in Iowa by high school graduate or higher, population 25 and over using official data, and cite the source.
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Questions

Which county has the highest high school graduate or higher, population 25 and over?

Story County, with 96.9% in 2021, according to the U.S. Census Bureau.

Which county has the lowest high school graduate or higher, population 25 and over?

Buena Vista County, with 79.4% 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 B15003: population 25 years and over with a high school diploma, GED or higher as a percentage of the population 25 years and over, calculated with stored inputs. Retrieved 2026-10-12.

High school graduate or higher, population 25 and over: other rankings

Counties in Iowa: more rankings