Data / Rankings / Median age / Counties in Illinois

Counties in Illinois by median age

Hardin County had the highest median age of 102 counties in 2023, at 55 years. Champaign County had the lowest, at 30.9 years. The median was 42.5 years and the figure for Illinois was 38.9 years. Source: the U.S. Census Bureau.

Highest55Hardin County
Lowest30.9Champaign County
Median42.5102 counties
Illinois38.9History

Top 40 counties, 2023

CSVChart (SVG)

Hardin CountyHardin County: 55 years55Jo Daviess CountyJo Daviess County: 50.9 years50.9Pope CountyPope County: 50.8 years50.8Henderson CountyHenderson County: 49.8 years49.8Schuyler CountySchuyler County: 48.8 years48.8Calhoun CountyCalhoun County: 48.5 years48.5Gallatin CountyGallatin County: 47.3 years47.3Putnam CountyPutnam County: 47.2 years47.2Edgar CountyEdgar County: 46.4 years46.4Hancock CountyHancock County: 46.3 years46.3Marshall CountyMarshall County: 45.9 years45.9Alexander CountyAlexander County: 45.8 years45.8Mason CountyMason County: 45.5 years45.5Shelby CountyShelby County: 45.5 years45.5Stephenson CountyStephenson County: 45.2 years45.2Massac CountyMassac County: 45 years45Carroll CountyCarroll County: 44.9 years44.9Edwards CountyEdwards County: 44.6 years44.6Stark CountyStark County: 44.6 years44.6Mercer CountyMercer County: 44.5 years44.5Iroquois CountyIroquois County: 44.4 years44.4White CountyWhite County: 44.4 years44.4Macoupin CountyMacoupin County: 44.3 years44.3Scott CountyScott County: 44.3 years44.3Union CountyUnion County: 44.3 years44.3Jasper CountyJasper County: 44.2 years44.2Washington CountyWashington County: 44.2 years44.2Bureau CountyBureau County: 44.1 years44.1De Witt CountyDe Witt County: 44 years44Fulton CountyFulton County: 43.7 years43.7Hamilton CountyHamilton County: 43.5 years43.5Franklin CountyFranklin County: 43.4 years43.4Henry CountyHenry County: 43.4 years43.4Whiteside CountyWhiteside County: 43.4 years43.4Jersey CountyJersey County: 43.2 years43.2Saline CountySaline County: 43.2 years43.2Greene CountyGreene County: 43.1 years43.1Wayne CountyWayne County: 43.1 years43.1Lee CountyLee County: 43 years43Randolph CountyRandolph County: 43 years43
years. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

RankCounties2023
years		Change on 2022
1Hardin County55+1.1
2Jo Daviess County50.9+0.1
3Pope County50.8+1.1
4Henderson County49.8+0.2
5Schuyler County48.8+0.6
6Calhoun County48.5+0.4
7Gallatin County47.3+0.4
8Putnam County47.2-0.2
9Edgar County46.4+0.4
10Hancock County46.3+0.4
11Marshall County45.9-0.3
12Alexander County45.8+0.9
13Mason County45.5+0.1
13Shelby County45.5+0.6
15Stephenson County45.2-0.4
16Massac County45+0.9
17Carroll County44.9-0.1
18Edwards County44.6+0.4
18Stark County44.6-0.2
20Mercer County44.5-0.2
21Iroquois County44.4-0.1
21White County44.4-0.3
23Macoupin County44.3+0.3
23Scott County44.3-0.4
23Union County44.3-0.4
26Jasper County44.2+0.2
26Washington County44.2+0.2
28Bureau County44.1+0.1
29De Witt County440
30Fulton County43.7+0.1
31Hamilton County43.5+0.5
32Franklin County43.4+0.2
32Henry County43.4-0.1
32Whiteside County43.4-0.1
35Jersey County43.2+0.4
35Saline County43.20
37Greene County43.1+0.4
37Wayne County43.1+0.2
39Lee County43+0.2
39Randolph County430
39Wabash County43-0.8
42Pike County42.9+0.1
43Menard County42.80
44Christian County42.7+0.5
44Johnson County42.7+0.4
44Pulaski County42.7-1.2
47Montgomery County42.6-0.1
48Ford County42.5+0.5
48Monroe County42.50
48Piatt County42.5+0.7
48Richland County42.5+0.3
52Crawford County42.4+0.2
52Knox County42.4+0.1
54Cumberland County42.3-0.3
55Perry County42.20
56LaSalle County42.1+0.2
57Clark County42+0.6
57Ogle County42-0.3
59Livingston County41.90
60Fayette County41.7-0.4
60Tazewell County41.7+0.1
62Clay County41.5-0.3
62Morgan County41.5+0.1
64Clinton County41.4+0.4
64Williamson County41.4+0.2
66Marion County41.3-0.6
67Vermilion County41.2+0.4
68Adams County41.1-0.2
68Jefferson County41.1-0.1
70Brown County40.9+2.4
70Macon County40.9+0.2
72Sangamon County40.8+0.2
73Lawrence County40.6-0.3
74Logan County40.5+0.2
74Woodford County40.5+0.4
76Bond County40.4+0.4
76McHenry County40.4-0.1
76Moultrie County40.4-0.1
79Rock Island County40.3+0.1
80Madison County40.2+0.3
81DuPage County40+0.1
82Winnebago County39.7+0.2
83Boone County39.5+0.5
83Effingham County39.5+0.2
83St. Clair County39.5+0.1
86Kankakee County39+0.1
87Douglas County38.9+0.3
87Lake County38.9+0.2
87Will County38.9+0.2
90Warren County38.7-1.4
91Grundy County38.6-0.2
91Kane County38.6+0.3
93Coles County38.2+0.8
94Cass County38.1-0.7
94Peoria County38.10
96Cook County37.8+0.3
97Kendall County36-0.1
98McDonough County35.1+0.2
99McLean County34.2+0.2
100Jackson County32.9+0.3
101DeKalb County32.6+0.8
102Champaign County30.9+0.1

Other periods

About this ranking

Age that divides the resident population into two halves of equal size. Spain and the EU: on 1 January. United States: American Community Survey five-year estimate, where the period shown is the last year of the five-year span.

Every value in the ranking comes from the same publisher and the same period, so the counties are compared on one definition. Equal values share a rank.

How to cite

U.S. Census Bureau. American Community Survey 5-year estimates, table B01002: median age, total population. https://www2.census.gov/programs-surveys/acs/summary_file/2023/table-based-SF/data/5YRData/acsdt5y2023-b01002.dat. Retrieved 2026-10-08.

Use this data in your AI agent

Invokely serves this figure to AI assistants through MCP and to code through a REST API, with the source and citation attached. Ask your assistant:

Rank Counties in Illinois by median age using official data, and cite the source.
rank_places {"indicator":"median_age","level":"province","within":"Illinois","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=median_age&level=province&within=Illinois&limit=10

Connect Claude, ChatGPT or Cursor in one step. The trial answers 25 calls a day without an account.

Questions

Which county has the highest median age?

Hardin County, with 55 years in 2023, according to the U.S. Census Bureau.

Which county has the lowest median age?

Champaign County, with 30.9 years in 2023.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, American Community Survey 5-year estimates, table B01002: median age, total population. Retrieved 2026-10-08.

Median age: other rankings

Counties in Illinois: more rankings