RANKING · 2010 CENSUS · 99 SHOWN OF 99

Oldest by median age, Iowa counties · 2010

Iowa counties ranked by median age of residents (2010 ACS). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide. The median across all 99 is 42.5.

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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, IAIA18,07748.1+11%

02Calhoun County, IAIA9,56247.8+13%

03Pocahontas County, IAIA6,81947.6+12%

04Monona County, IAIA8,53947.5+10%

05Audubon County, IAIA5,50947.0+11%

06Cherokee County, IAIA11,36947.0+13%

07Adams County, IAIA3,61746.7+11%

08Kossuth County, IAIA14,32246.6+13%

09Sac County, IAIA9,52546.6+11%

10Greene County, IAIA8,65845.6+11%

11Ringgold County, IAIA4,64245.6+6%

12Shelby County, IAIA11,68945.4+12%

13Adair County, IAIA7,40345.3+8%

14Wayne County, IAIA6,73845.3+5%

15Cass County, IAIA12,96045.1+8%

16Fremont County, IAIA6,52245.1+9%

17Clayton County, IAIA16,84545.0+12%

18Guthrie County, IAIA10,78244.8+7%

19Hancock County, IAIA10,52844.8+13%

20Ida County, IAIA6,77744.8+8%

21Taylor County, IAIA5,83544.6+7%

22Montgomery County, IAIA10,00244.6+10%

23Wright County, IAIA12,80144.4+7%

24Humboldt County, IAIA9,40944.3+7%

25Appanoose County, IAIA12,07744.2+9%

26Lucas County, IAIA8,84744.1+11%

27Mitchell County, IAIA10,65044.0+8%

28Allamakee County, IAIA14,23844.0+11%

29Jackson County, IAIA19,28844.0+13%

30Palo Alto County, IAIA8,89943.9+8%

31Butler County, IAIA14,04943.8+6%

32Keokuk County, IAIA9,79743.8+9%

33Worth County, IAIA7,33843.8+8%

34Chickasaw County, IAIA11,66343.7+10%

35Hardin County, IAIA16,45543.7+8%

36Page County, IAIA14,85643.7+9%

37O'Brien County, IAIA14,22043.6+7%

38Jefferson County, IAIA15,29143.5+6%

39Osceola County, IAIA5,98043.5+10%

40Winnebago County, IAIA10,25143.5+9%

41Cerro Gordo County, IAIA42,37243.3+10%

42Floyd County, IAIA14,90143.3+7%

43Van Buren County, IAIA7,13143.3+6%

44Fayette County, IAIA19,04743.2+10%

45Grundy County, IAIA12,36143.0+5%

46Harrison County, IAIA14,62342.9+10%

47Franklin County, IAIA9,86842.8+4%

48Jones County, IAIA21,25342.7+11%

49Lee County, IAIA32,30642.6+8%

50Clay County, IAIA16,20242.5+8%

51Cedar County, IAIA18,35942.4+8%

52Iowa County, IAIA16,50442.4+9%

53Carroll County, IAIA20,30342.3+9%

54Hamilton County, IAIA14,94442.3+8%

55Delaware County, IAIA17,67442.1+13%

56Howard County, IAIA9,41542.1+7%

57Monroe County, IAIA7,40642.1+6%

58Tama County, IAIA16,79641.8+7%

59Jasper County, IAIA38,15341.6+8%

60Washington County, IAIA22,66741.6+7%

61Des Moines County, IAIA38,07741.5+7%

62Clinton County, IAIA46,00241.4+8%

63Mills County, IAIA14,79341.2+8%

64Plymouth County, IAIA25,69741.2+9%

65Poweshiek County, IAIA18,36841.0+7%

66Emmet County, IAIA9,10741.0+4%

67Union County, IAIA11,82940.9+2%

68Benton County, IAIA26,00440.9+10%

69Boone County, IAIA26,79940.8+6%

70Clarke County, IAIA9,57440.2+4%

71Henry County, IAIA19,34940.2+8%

72Webster County, IAIA36,83840.0+6%

73Louisa County, IAIA10,41639.8+11%

74Madison County, IAIA17,27039.8+5%

75Wapello County, IAIA35,21039.8+2%

76Marshall County, IAIA39,89039.6+3%

77Winneshiek County, IAIA19,73339.4+10%

78Bremer County, IAIA25,29639.3+3%

79Buchanan County, IAIA20,88339.0+7%

80Mahaska County, IAIA21,88038.9+5%

81Lyon County, IAIA12,35438.7+2%

82Davis County, IAIA9,23038.60%

83Dubuque County, IAIA99,38138.6+6%

84Marion County, IAIA34,19238.6+4%

85Pottawattamie County, IAIA92,99638.5+5%

86Crawford County, IAIA16,23738.4+1%

87Warren County, IAIA57,33138.3+6%

88Decatur County, IAIA7,65538.2+5%

89Muscatine County, IAIA41,85338.2+6%

90Scott County, IAIA175,25937.7+6%

91Buena Vista County, IAIA20,44937.1+2%

92Linn County, IAIA232,02836.5+4%

93Woodbury County, IAIA106,64935.1+3%

94Polk County, IAIA516,54634.7+1%

95Black Hawk County, IAIA131,53234.40%

96Dallas County, IAIA118,45734.3−2%

97Sioux County, IAIA36,77432.70%

98Johnson County, IAIA160,04429.3+3%

99Story County, IAIA101,29126.7+1%

SHOWING 1–99 OF 99

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