RANKING · 1990 CENSUS · 99 SHOWN OF 99

Youngest by median age, Iowa counties · 1990

Iowa counties with the youngest median age (1990 ACS). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide. The median across all 99 is 36.2.

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SAME RANKING BYCities States Metros ZIP codes

RELATEDLargest foreign-born population Most residents with a disability Largest veteran population Most uninsured people Largest senior population Most unmarried people

YEAR1990 2000 2010 2020 2024

RANKPLACESTATEPOPMEDIAN AGEVS –

01Story County, IAIA101,29125.9–

02Johnson County, IAIA160,04427.3–

03Sioux County, IAIA36,77431.1–

04Winneshiek County, IAIA19,73331.5–

05Scott County, IAIA175,25932.4–

06Polk County, IAIA516,54632.5–

07Delaware County, IAIA17,67432.5–

08Warren County, IAIA57,33132.8–

09Black Hawk County, IAIA131,53232.9–

10Woodbury County, IAIA106,64933.1–

11Dubuque County, IAIA99,38133.1–

12Linn County, IAIA232,02833.1–

13Muscatine County, IAIA41,85333.1–

14Buchanan County, IAIA20,88333.5–

15Pottawattamie County, IAIA92,99633.6–

16Buena Vista County, IAIA20,44933.9–

17Marion County, IAIA34,19234.0–

18Plymouth County, IAIA25,69734.1–

19Louisa County, IAIA10,41634.2–

20Carroll County, IAIA20,30334.2–

21Poweshiek County, IAIA18,36834.5–

22Henry County, IAIA19,34934.6–

23Dallas County, IAIA118,45734.6–

24Jones County, IAIA21,25334.6–

25Benton County, IAIA26,00434.7–

26Mahaska County, IAIA21,88034.8–

27Lyon County, IAIA12,35434.8–

28Jackson County, IAIA19,28835.0–

29Mills County, IAIA14,79335.1–

30Clinton County, IAIA46,00235.1–

31Clay County, IAIA16,20235.1–

32Bremer County, IAIA25,29635.2–

33Cerro Gordo County, IAIA42,37235.3–

34Crawford County, IAIA16,23735.4–

35Decatur County, IAIA7,65535.4–

36Hancock County, IAIA10,52835.5–

37Webster County, IAIA36,83835.5–

38Washington County, IAIA22,66735.6–

39Chickasaw County, IAIA11,66335.7–

40Winnebago County, IAIA10,25135.9–

41Clayton County, IAIA16,84535.9–

42Des Moines County, IAIA38,07736.0–

43Lee County, IAIA32,30636.0–

44Davis County, IAIA9,23036.0–

45Emmet County, IAIA9,10736.1–

46Jasper County, IAIA38,15336.1–

47Cedar County, IAIA18,35936.1–

48Madison County, IAIA17,27036.2–

49Osceola County, IAIA5,98036.2–

50Fayette County, IAIA19,04736.2–

51Allamakee County, IAIA14,23836.3–

52Iowa County, IAIA16,50436.5–

53Kossuth County, IAIA14,32236.6–

54Harrison County, IAIA14,62336.6–

55Boone County, IAIA26,79936.6–

56Union County, IAIA11,82936.7–

57Marshall County, IAIA39,89036.8–

58Clarke County, IAIA9,57436.9–

59Jefferson County, IAIA15,29136.9–

60O'Brien County, IAIA14,22036.9–

61Ida County, IAIA6,77737.0–

62Shelby County, IAIA11,68937.1–

63Cherokee County, IAIA11,36937.2–

64Hamilton County, IAIA14,94437.2–

65Wapello County, IAIA35,21037.2–

66Tama County, IAIA16,79637.3–

67Palo Alto County, IAIA8,89937.4–

68Howard County, IAIA9,41537.4–

69Keokuk County, IAIA9,79737.5–

70Monroe County, IAIA7,40637.6–

71Sac County, IAIA9,52537.7–

72Van Buren County, IAIA7,13137.7–

73Floyd County, IAIA14,90137.8–

74Butler County, IAIA14,04937.9–

75Franklin County, IAIA9,86837.9–

76Appanoose County, IAIA12,07738.0–

77Hardin County, IAIA16,45538.2–

78Montgomery County, IAIA10,00238.3–

79Fremont County, IAIA6,52238.4–

80Worth County, IAIA7,33838.4–

81Page County, IAIA14,85638.5–

82Cass County, IAIA12,96038.5–

83Mitchell County, IAIA10,65038.6–

84Lucas County, IAIA8,84738.6–

85Humboldt County, IAIA9,40938.7–

86Grundy County, IAIA12,36138.9–

87Wright County, IAIA12,80138.9–

88Pocahontas County, IAIA6,81939.1–

89Adair County, IAIA7,40339.3–

90Greene County, IAIA8,65839.3–

91Dickinson County, IAIA18,07739.4–

92Calhoun County, IAIA9,56239.6–

93Taylor County, IAIA5,83539.7–

94Guthrie County, IAIA10,78240.1–

95Audubon County, IAIA5,50940.4–

96Adams County, IAIA3,61740.5–

97Monona County, IAIA8,53941.3–

98Wayne County, IAIA6,73841.8–

99Ringgold County, IAIA4,64242.4–

SHOWING 1–99 OF 99

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UPDATED 2026-09-11 · DATA: US CENSUS BUREAU DECENNIAL CENSUS