RANKING · 2020 CENSUS · 102 SHOWN OF 102

Youngest by median age, Illinois counties · 2020

Illinois counties with the youngest median age (2020 ACS). This list covers the 102 counties in Illinois that qualify, ranked against each other statewide. The median across all 102 is 42.9.

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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

01Champaign County, ILIL209,97230.8+8%

02DeKalb County, ILIL101,83534.3+21%

03Jackson County, ILIL52,50134.9+27%

04McLean County, ILIL171,41935.1+15%

05Kendall County, ILIL145,47035.8+5%

06McDonough County, ILIL25,91637.0+28%

07Cook County, ILIL5,194,62537.4+11%

08Kane County, ILIL525,75738.3+19%

09Peoria County, ILIL178,55338.5+7%

10Grundy County, ILIL54,05238.7+7%

11Coles County, ILIL46,60738.8+26%

12Cass County, ILIL12,46339.0+5%

13Will County, ILIL712,25339.0+17%

14St. Clair County, ILIL250,70839.3+11%

15Lake County, ILIL719,33939.3+16%

16Douglas County, ILIL19,88039.6+6%

17Kankakee County, ILIL105,52539.6+12%

18Boone County, ILIL53,56839.9+16%

19Winnebago County, ILIL283,67440.0+11%

20DuPage County, ILIL934,29840.1+14%

21Brown County, ILIL6,40140.1+14%

22Madison County, ILIL263,11040.3+9%

23Effingham County, ILIL34,51940.5+13%

24Rock Island County, ILIL141,86940.6+7%

25McHenry County, ILIL317,75140.8+19%

26Warren County, ILIL16,22240.9+8%

27Sangamon County, ILIL194,17041.1+10%

28Moultrie County, ILIL14,37141.1+6%

29Woodford County, ILIL38,11141.1+9%

30Clinton County, ILIL37,12841.3+13%

31Adams County, ILIL64,26741.3+8%

32Macon County, ILIL99,30041.3+9%

33Lawrence County, ILIL13,79041.4+1%

34Fayette County, ILIL20,79041.4+10%

35Bond County, ILIL16,95941.7+13%

36Vermilion County, ILIL71,25941.7+10%

37Logan County, ILIL27,18241.9+13%

38Ogle County, ILIL51,39941.9+13%

39Tazewell County, ILIL130,04941.9+10%

40Williamson County, ILIL67,22541.9+8%

41Perry County, ILIL20,16042.0+12%

42Jefferson County, ILIL36,14742.2+12%

43Livingston County, ILIL35,05742.4+14%

44LaSalle County, ILIL107,77342.5+12%

45Morgan County, ILIL32,51542.5+12%

46Marion County, ILIL36,38242.7+11%

47Monroe County, ILIL34,84042.8+14%

48Cumberland County, ILIL10,20842.8+15%

49Johnson County, ILIL13,36342.8+17%

50Wayne County, ILIL15,88242.8+7%

51Clay County, ILIL12,79342.9+8%

52Ford County, ILIL13,21642.9+9%

53Pike County, ILIL14,23143.0+8%

54Crawford County, ILIL18,64843.1+12%

55Randolph County, ILIL29,92143.1+15%

56Wabash County, ILIL10,90743.1+11%

57Saline County, ILIL22,77243.2+8%

58Hamilton County, ILIL7,85943.2+6%

59Henry County, ILIL48,09543.2+10%

60Richland County, ILIL15,21943.2+10%

61Knox County, ILIL47,76743.3+10%

62Clark County, ILIL15,11443.4+11%

63Christian County, ILIL33,44343.5+12%

64De Witt County, ILIL15,11843.6+13%

65Edwards County, ILIL5,89843.6+8%

66Menard County, ILIL11,86343.6+15%

67Lee County, ILIL32,91443.7+15%

68Montgomery County, ILIL28,07643.7+15%

69Piatt County, ILIL16,79143.7+10%

70Franklin County, ILIL36,91644.1+9%

71Jasper County, ILIL9,03244.1+16%

72Fulton County, ILIL32,90144.2+13%

73Jersey County, ILIL21,16044.2+18%

74Greene County, ILIL11,31344.3+17%

75Massac County, ILIL13,50244.3+12%

76Macoupin County, ILIL43,74844.4+14%

77Scott County, ILIL4,86644.4+14%

78Washington County, ILIL13,56444.4+14%

79Whiteside County, ILIL54,12144.4+15%

80Iroquois County, ILIL26,15044.5+12%

81Bureau County, ILIL32,51044.8+13%

82Union County, ILIL16,65644.9+11%

83Mercer County, ILIL15,22945.1+14%

84White County, ILIL13,25045.1+7%

85Shelby County, ILIL20,57645.4+16%

86Edgar County, ILIL16,32345.5+16%

87Stark County, ILIL5,31945.5+14%

88Stephenson County, ILIL43,22045.9+19%

89Pulaski County, ILIL4,82046.0+22%

90Hancock County, ILIL16,80346.1+14%

91Mason County, ILIL12,41146.1+17%

92Marshall County, ILIL11,47346.2+13%

93Carroll County, ILIL15,41946.5+14%

94Putnam County, ILIL5,61947.0+19%

95Gallatin County, ILIL4,61647.3+16%

96Schuyler County, ILIL6,65747.5+16%

97Calhoun County, ILIL4,30049.0+21%

98Alexander County, ILIL4,57049.1+29%

99Henderson County, ILIL5,98450.1+22%

100Jo Daviess County, ILIL21,59450.1+20%

101Hardin County, ILIL3,58852.2+24%

102Pope County, ILIL3,67252.5+28%

SHOWING 1–102 OF 102

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