RANKING · 1990 CENSUS · 99 SHOWN OF 99

Oldest by median age, Iowa counties · 1990

Iowa counties ranked by median age of residents (1990 ACS). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide.

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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 –

01Ringgold County, IAIA4,64242.4–

02Wayne County, IAIA6,73841.8–

03Monona County, IAIA8,53941.3–

04Adams County, IAIA3,61740.5–

05Audubon County, IAIA5,50940.4–

06Guthrie County, IAIA10,78240.1–

07Taylor County, IAIA5,83539.7–

08Calhoun County, IAIA9,56239.6–

09Dickinson County, IAIA18,07739.4–

10Greene County, IAIA8,65839.3–

11Adair County, IAIA7,40339.3–

12Pocahontas County, IAIA6,81939.1–

13Wright County, IAIA12,80138.9–

14Grundy County, IAIA12,36138.9–

15Humboldt County, IAIA9,40938.7–

16Lucas County, IAIA8,84738.6–

17Mitchell County, IAIA10,65038.6–

18Cass County, IAIA12,96038.5–

19Page County, IAIA14,85638.5–

20Worth County, IAIA7,33838.4–

21Fremont County, IAIA6,52238.4–

22Montgomery County, IAIA10,00238.3–

23Hardin County, IAIA16,45538.2–

24Appanoose County, IAIA12,07738.0–

25Franklin County, IAIA9,86837.9–

26Butler County, IAIA14,04937.9–

27Floyd County, IAIA14,90137.8–

28Van Buren County, IAIA7,13137.7–

29Sac County, IAIA9,52537.7–

30Monroe County, IAIA7,40637.6–

31Keokuk County, IAIA9,79737.5–

32Howard County, IAIA9,41537.4–

33Palo Alto County, IAIA8,89937.4–

34Tama County, IAIA16,79637.3–

35Wapello County, IAIA35,21037.2–

36Hamilton County, IAIA14,94437.2–

37Cherokee County, IAIA11,36937.2–

38Shelby County, IAIA11,68937.1–

39Ida County, IAIA6,77737.0–

40O'Brien County, IAIA14,22036.9–

41Jefferson County, IAIA15,29136.9–

42Clarke County, IAIA9,57436.9–

43Marshall County, IAIA39,89036.8–

44Union County, IAIA11,82936.7–

45Boone County, IAIA26,79936.6–

46Harrison County, IAIA14,62336.6–

47Kossuth County, IAIA14,32236.6–

48Iowa County, IAIA16,50436.5–

49Allamakee County, IAIA14,23836.3–

50Fayette County, IAIA19,04736.2–

51Osceola County, IAIA5,98036.2–

52Madison County, IAIA17,27036.2–

53Cedar County, IAIA18,35936.1–

54Jasper County, IAIA38,15336.1–

55Emmet County, IAIA9,10736.1–

56Davis County, IAIA9,23036.0–

57Lee County, IAIA32,30636.0–

58Des Moines County, IAIA38,07736.0–

59Clayton County, IAIA16,84535.9–

60Winnebago County, IAIA10,25135.9–

61Chickasaw County, IAIA11,66335.7–

62Washington County, IAIA22,66735.6–

63Webster County, IAIA36,83835.5–

64Hancock County, IAIA10,52835.5–

65Decatur County, IAIA7,65535.4–

66Crawford County, IAIA16,23735.4–

67Cerro Gordo County, IAIA42,37235.3–

68Bremer County, IAIA25,29635.2–

69Clay County, IAIA16,20235.1–

70Clinton County, IAIA46,00235.1–

71Mills County, IAIA14,79335.1–

72Jackson County, IAIA19,28835.0–

73Lyon County, IAIA12,35434.8–

74Mahaska County, IAIA21,88034.8–

75Benton County, IAIA26,00434.7–

76Jones County, IAIA21,25334.6–

77Dallas County, IAIA118,45734.6–

78Henry County, IAIA19,34934.6–

79Poweshiek County, IAIA18,36834.5–

80Carroll County, IAIA20,30334.2–

81Louisa County, IAIA10,41634.2–

82Plymouth County, IAIA25,69734.1–

83Marion County, IAIA34,19234.0–

84Buena Vista County, IAIA20,44933.9–

85Pottawattamie County, IAIA92,99633.6–

86Buchanan County, IAIA20,88333.5–

87Muscatine County, IAIA41,85333.1–

88Linn County, IAIA232,02833.1–

89Dubuque County, IAIA99,38133.1–

90Woodbury County, IAIA106,64933.1–

91Black Hawk County, IAIA131,53232.9–

92Warren County, IAIA57,33132.8–

93Delaware County, IAIA17,67432.5–

94Polk County, IAIA516,54632.5–

95Scott County, IAIA175,25932.4–

96Winneshiek County, IAIA19,73331.5–

97Sioux County, IAIA36,77431.1–

98Johnson County, IAIA160,04427.3–

99Story County, IAIA101,29125.9–

SHOWING 1–99 OF 99

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU DECENNIAL CENSUS