RANKING · 2025 ESTIMATES · 99 SHOWN OF 99

Fastest growing, Iowa counties

Iowa counties ranked by population growth from the 2020 census to 2025. This list covers the 99 counties in Iowa that qualify, ranked against each other statewide.

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SAME RANKING BYCities States Metros

RELATEDLargest by population Fastest shrinking Most population gained Most population lost Most densely populated Most sparsely populated

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION GROWTHVS 2000

01Dallas County, IAIA118,457+18.8%−49%

02Warren County, IAIA57,331+9.4%−27%

03Polk County, IAIA516,546+4.9%−66%

04Johnson County, IAIA160,044+4.7%−70%

05Madison County, IAIA17,270+4.4%−65%

06Wayne County, IAIA6,738+3.7%−178%

07Lyon County, IAIA12,354+3.5%−323%

08Jones County, IAIA21,253+2.9%−26%

09Story County, IAIA101,291+2.8%−64%

10Sioux County, IAIA36,774+2.5%−55%

11Lucas County, IAIA8,847+2.5%−36%

12Marion County, IAIA34,192+2.3%−66%

13Mills County, IAIA14,793+2.1%−79%

14Dickinson County, IAIA18,077+2.1%−79%

15Benton County, IAIA26,004+1.7%−87%

16Buchanan County, IAIA20,883+1.5%+29%

17Guthrie County, IAIA10,782+1.5%−61%

18Davis County, IAIA9,230+1.3%−52%

19Allamakee County, IAIA14,238+1.3%−79%

20Bremer County, IAIA25,296+1.2%−45%

21Delaware County, IAIA17,674+1.1%−48%

22Jasper County, IAIA38,153+0.9%−87%

23Mitchell County, IAIA10,650+0.8%−263%

24Linn County, IAIA232,028+0.8%−94%

25Woodbury County, IAIA106,649+0.7%−88%

26Washington County, IAIA22,667+0.5%−92%

27Scott County, IAIA175,259+0.3%−93%

28Boone County, IAIA26,799+0.3%−92%

29Black Hawk County, IAIA131,532+0.3%−91%

30Harrison County, IAIA14,623+0.3%−96%

31O'Brien County, IAIA14,220+0.3%−112%

32Grundy County, IAIA12,361+0.3%−91%

33Decatur County, IAIA7,655+0.1%−97%

34Dubuque County, IAIA99,381+0.1%−96%

35Plymouth County, IAIA25,697-0.0%−100%

36Webster County, IAIA36,838-0.4%+64%

37Ringgold County, IAIA4,642-0.5%−150%

38Shelby County, IAIA11,689-0.5%+13%

39Marshall County, IAIA39,890-0.5%−120%

40Howard County, IAIA9,415-0.6%−145%

41Hamilton County, IAIA14,944-0.6%−128%

42Wapello County, IAIA35,210-0.6%−163%

43Pottawattamie County, IAIA92,996-0.7%−112%

44Cedar County, IAIA18,359-0.8%−117%

45Iowa County, IAIA16,504-0.9%−113%

46Clinton County, IAIA46,002-1.0%−44%

47Van Buren County, IAIA7,131-1.0%−158%

48Jackson County, IAIA19,288-1.0%−158%

49Taylor County, IAIA5,835-1.0%−53%

50Palo Alto County, IAIA8,899-1.1%−78%

51Wright County, IAIA12,801-1.1%−341%

52Clay County, IAIA16,202-1.1%−8%

53Clayton County, IAIA16,845-1.2%−41%

54Adair County, IAIA7,403-1.2%−37%

55Fremont County, IAIA6,522-1.3%−52%

56Cass County, IAIA12,960-1.3%−57%

57Greene County, IAIA8,658-1.3%−140%

58Mahaska County, IAIA21,880-1.4%−137%

59Worth County, IAIA7,338-1.4%+37%

60Franklin County, IAIA9,868-1.5%−74%

61Poweshiek County, IAIA18,368-1.6%+38%

62Winneshiek County, IAIA19,733-1.7%−176%

63Crawford County, IAIA16,237-1.7%−275%

64Cerro Gordo County, IAIA42,372-1.8%+186%

65Clarke County, IAIA9,574-1.8%−117%

66Buena Vista County, IAIA20,449-1.8%−180%

67Appanoose County, IAIA12,077-1.9%+1117%

68Humboldt County, IAIA9,409-2.0%−44%

69Tama County, IAIA16,796-2.0%−150%

70Butler County, IAIA14,049-2.0%−27%

71Des Moines County, IAIA38,077-2.1%+247%

72Carroll County, IAIA20,303-2.2%+23480%

73Monroe County, IAIA7,406-2.3%+87%

74Page County, IAIA14,856-2.3%−471%

75Adams County, IAIA3,617-2.3%−70%

76Keokuk County, IAIA9,797-2.4%+22%

77Fayette County, IAIA19,047-2.4%−413%

78Jefferson County, IAIA15,291-2.4%+200%

79Monona County, IAIA8,539-2.4%+1636%

80Hancock County, IAIA10,528-2.5%−42%

81Cherokee County, IAIA11,369-2.5%−67%

82Hardin County, IAIA16,455-2.5%+70%

83Union County, IAIA11,829-2.5%−26%

84Chickasaw County, IAIA11,663-2.9%+93%

85Audubon County, IAIA5,509-2.9%−58%

86Sac County, IAIA9,525-2.9%−54%

87Emmet County, IAIA9,107-3.0%−36%

88Montgomery County, IAIA10,002-3.2%+26%

89Muscatine County, IAIA41,853-3.2%−170%

90Ida County, IAIA6,777-3.3%−48%

91Kossuth County, IAIA14,322-3.4%−56%

92Osceola County, IAIA5,980-3.4%−6%

93Pocahontas County, IAIA6,819-3.7%−60%

94Calhoun County, IAIA9,562-3.7%+8%

95Lee County, IAIA32,306-3.7%+127%

96Louisa County, IAIA10,416-3.9%−176%

97Winnebago County, IAIA10,251-4.0%+22%

98Floyd County, IAIA14,901-4.6%+402%

99Henry County, IAIA19,349-5.5%−196%

SHOWING 1–99 OF 99

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES