RANKING · 2020 CENSUS · 99 SHOWN OF 99

Oldest by median age, Iowa counties · 2020

Iowa counties ranked by median age of residents (2020 ACS). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide. The median across all 99 is 42.6.

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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 2000

01Dickinson County, IAIA18,07749.1+13%

02Audubon County, IAIA5,50947.3+12%

03Clayton County, IAIA16,84546.7+16%

04Guthrie County, IAIA10,78246.5+11%

05Shelby County, IAIA11,68946.4+15%

06Jefferson County, IAIA15,29146.3+13%

07Kossuth County, IAIA14,32246.3+12%

08Sac County, IAIA9,52546.3+10%

09Cherokee County, IAIA11,36946.0+10%

10Ringgold County, IAIA4,64246.0+6%

11Monona County, IAIA8,53945.9+7%

12Fremont County, IAIA6,52245.7+11%

13Adams County, IAIA3,61745.6+9%

14Cass County, IAIA12,96045.5+9%

15Appanoose County, IAIA12,07745.4+12%

16Hancock County, IAIA10,52845.4+14%

17Butler County, IAIA14,04945.3+10%

18Pocahontas County, IAIA6,81945.3+7%

19Jackson County, IAIA19,28845.2+16%

20Montgomery County, IAIA10,00245.1+12%

21Greene County, IAIA8,65844.9+10%

22Cerro Gordo County, IAIA42,37244.7+14%

23Lee County, IAIA32,30644.4+12%

24Van Buren County, IAIA7,13144.4+9%

25Calhoun County, IAIA9,56244.3+4%

26Ida County, IAIA6,77744.1+6%

27Adair County, IAIA7,40344.0+5%

28Fayette County, IAIA19,04744.0+12%

29Chickasaw County, IAIA11,66343.8+10%

30Mitchell County, IAIA10,65043.6+7%

31Cedar County, IAIA18,35943.6+11%

32Floyd County, IAIA14,90143.6+8%

33Palo Alto County, IAIA8,89943.6+7%

34Taylor County, IAIA5,83543.5+5%

35Delaware County, IAIA17,67443.5+17%

36Hardin County, IAIA16,45543.5+7%

37Harrison County, IAIA14,62343.5+12%

38Keokuk County, IAIA9,79743.5+9%

39Lucas County, IAIA8,84743.4+9%

40Jones County, IAIA21,25343.3+12%

41Page County, IAIA14,85643.3+8%

42Worth County, IAIA7,33843.3+6%

43Allamakee County, IAIA14,23843.2+9%

44Emmet County, IAIA9,10743.1+9%

45Mills County, IAIA14,79343.1+13%

46Osceola County, IAIA5,98043.1+9%

47Des Moines County, IAIA38,07742.9+10%

48Clay County, IAIA16,20242.8+9%

49Hamilton County, IAIA14,94442.8+9%

50Clinton County, IAIA46,00242.6+12%

51Iowa County, IAIA16,50442.6+10%

52Monroe County, IAIA7,40642.6+7%

53Winneshiek County, IAIA19,73342.6+19%

54Carroll County, IAIA20,30342.5+10%

55Franklin County, IAIA9,86842.5+3%

56Benton County, IAIA26,00442.3+14%

57Grundy County, IAIA12,36142.3+4%

58Winnebago County, IAIA10,25142.3+6%

59Jasper County, IAIA38,15342.1+9%

60Louisa County, IAIA10,41642.1+17%

61O'Brien County, IAIA14,22042.0+3%

62Tama County, IAIA16,79642.0+7%

63Boone County, IAIA26,79941.8+8%

64Humboldt County, IAIA9,40941.8+1%

65Howard County, IAIA9,41541.7+6%

66Madison County, IAIA17,27041.2+9%

67Marion County, IAIA34,19241.1+10%

68Washington County, IAIA22,66741.1+6%

69Wright County, IAIA12,80141.0−1%

70Union County, IAIA11,82940.9+2%

71Henry County, IAIA19,34940.8+10%

72Poweshiek County, IAIA18,36840.7+6%

73Plymouth County, IAIA25,69740.6+7%

74Clarke County, IAIA9,57440.3+4%

75Wayne County, IAIA6,73840.3−6%

76Webster County, IAIA36,83840.2+7%

77Pottawattamie County, IAIA92,99640.1+10%

78Buchanan County, IAIA20,88339.8+9%

79Mahaska County, IAIA21,88039.7+7%

80Bremer County, IAIA25,29639.6+4%

81Decatur County, IAIA7,65539.5+9%

82Muscatine County, IAIA41,85339.5+9%

83Marshall County, IAIA39,89039.2+2%

84Wapello County, IAIA35,21039.10%

85Scott County, IAIA175,25939.0+10%

86Warren County, IAIA57,33138.8+8%

87Dubuque County, IAIA99,38138.7+6%

88Linn County, IAIA232,02838.0+8%

89Crawford County, IAIA16,23737.8−1%

90Lyon County, IAIA12,35437.7−1%

91Black Hawk County, IAIA131,53236.8+7%

92Davis County, IAIA9,23036.0−6%

93Polk County, IAIA516,54636.0+5%

94Woodbury County, IAIA106,64935.8+5%

95Buena Vista County, IAIA20,44935.7−2%

96Dallas County, IAIA118,45735.4+1%

97Sioux County, IAIA36,77433.4+2%

98Johnson County, IAIA160,04431.2+10%

99Story County, IAIA101,29126.9+2%

SHOWING 1–99 OF 99

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