RANKING · 2000 CENSUS · 102 SHOWN OF 102

Youngest by median age, Illinois counties · 2000

Illinois counties with the youngest median age (2000 ACS). This list covers the 102 counties in Illinois that qualify, ranked against each other statewide. The median across all 102 is 38.1.

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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 1990

01Jackson County, ILIL52,50127.5+4%

02DeKalb County, ILIL101,83528.4+4%

03Champaign County, ILIL209,97228.6+3%

04McDonough County, ILIL25,91629.0+6%

05McLean County, ILIL171,41930.5+5%

06Coles County, ILIL46,60730.8+3%

07Kane County, ILIL525,75732.2+4%

08Will County, ILIL712,25333.3+7%

09Cook County, ILIL5,194,62533.6+3%

10Lake County, ILIL719,33933.8+7%

11Kendall County, ILIL145,47034.1+6%

12McHenry County, ILIL317,75134.2+6%

13Boone County, ILIL53,56834.5+4%

14DuPage County, ILIL934,29835.2+9%

15Brown County, ILIL6,40135.2+5%

16Kankakee County, ILIL105,52535.2+7%

17St. Clair County, ILIL250,70835.3+10%

18Effingham County, ILIL34,51935.7+12%

19Winnebago County, ILIL283,67435.9+7%

20Peoria County, ILIL178,55336.0+6%

21Grundy County, ILIL54,05236.3+9%

22Clinton County, ILIL37,12836.6+11%

23Johnson County, ILIL13,36336.7+3%

24Bond County, ILIL16,95936.8+5%

25Madison County, ILIL263,11036.9+9%

26Logan County, ILIL27,18237.0+7%

27Cass County, ILIL12,46337.2+4%

28Cumberland County, ILIL10,20837.2+10%

29Ogle County, ILIL51,39937.2+10%

30Sangamon County, ILIL194,17037.3+9%

31Jersey County, ILIL21,16037.3+12%

32Livingston County, ILIL35,05737.3+9%

33Douglas County, ILIL19,88037.4+8%

34Monroe County, ILIL34,84037.5+10%

35Fayette County, ILIL20,79037.5+6%

36Jefferson County, ILIL36,14737.6+8%

37Perry County, ILIL20,16037.6+6%

38Randolph County, ILIL29,92137.6+11%

39Pulaski County, ILIL4,82037.7+8%

40Rock Island County, ILIL141,86937.8+8%

41Morgan County, ILIL32,51537.8+10%

42Warren County, ILIL16,22237.8+8%

43Woodford County, ILIL38,11137.8+11%

44Greene County, ILIL11,31337.9+5%

45Lee County, ILIL32,91437.9+10%

46Alexander County, ILIL4,57038.0+9%

47Macon County, ILIL99,30038.0+9%

48Menard County, ILIL11,86338.0+7%

49Vermilion County, ILIL71,25938.0+7%

50Jasper County, ILIL9,03238.1+10%

51LaSalle County, ILIL107,77338.1+7%

52Montgomery County, ILIL28,07638.1+8%

53Tazewell County, ILIL130,04938.1+10%

54Adams County, ILIL64,26738.3+7%

55Marion County, ILIL36,38238.4+9%

56De Witt County, ILIL15,11838.5+9%

57Stephenson County, ILIL43,22038.5+10%

58Whiteside County, ILIL54,12138.5+11%

59Crawford County, ILIL18,64838.6+4%

60Moultrie County, ILIL14,37138.7+5%

61Scott County, ILIL4,86638.8+8%

62Washington County, ILIL13,56438.8+8%

63Williamson County, ILIL67,22538.8+7%

64Christian County, ILIL33,44338.9+7%

65Macoupin County, ILIL43,74838.9+8%

66Wabash County, ILIL10,90739.0+12%

67Henry County, ILIL48,09539.1+9%

68Richland County, ILIL15,21939.1+10%

69Clark County, ILIL15,11439.2+6%

70Fulton County, ILIL32,90139.2+6%

71Edgar County, ILIL16,32339.3+5%

72Shelby County, ILIL20,57639.3+9%

73Ford County, ILIL13,21639.4+8%

74Knox County, ILIL47,76739.4+9%

75Mason County, ILIL12,41139.5+8%

76Mercer County, ILIL15,22939.5+9%

77Bureau County, ILIL32,51039.6+9%

78Iroquois County, ILIL26,15039.6+7%

79Massac County, ILIL13,50239.6+4%

80Piatt County, ILIL16,79139.6+10%

81Putnam County, ILIL5,61939.6+10%

82Clay County, ILIL12,79339.7+8%

83Pike County, ILIL14,23139.8+6%

84Saline County, ILIL22,77239.9+4%

85Stark County, ILIL5,31939.9+5%

86Wayne County, ILIL15,88239.9+7%

87Franklin County, ILIL36,91640.3+6%

88Hancock County, ILIL16,80340.3+8%

89Union County, ILIL16,65640.3+6%

90Calhoun County, ILIL4,30040.5+6%

91Edwards County, ILIL5,89840.5+8%

92Hamilton County, ILIL7,85940.6+3%

93Gallatin County, ILIL4,61640.7+2%

94Carroll County, ILIL15,41940.8+9%

95Lawrence County, ILIL13,79040.8+8%

96Marshall County, ILIL11,47340.9+9%

97Schuyler County, ILIL6,65740.9+8%

98Henderson County, ILIL5,98441.0+9%

99Pope County, ILIL3,67241.1+15%

100Jo Daviess County, ILIL21,59441.6+15%

101White County, ILIL13,25042.0+10%

102Hardin County, ILIL3,58842.1+13%

SHOWING 1–102 OF 102

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