Counties in Illinois by median age on 1 July (US county estimates)

Pope County had the highest median age on 1 July (US county estimates) of 102 counties in 2024, at 54.2 years. Champaign County had the lowest, at 30.9 years. The median was 43.1 years. Source: the U.S. Census Bureau.

Highest54.2Pope County

Lowest30.9Champaign County

Median43.1102 counties

Map of counties, 2024

Under 40
40 to 42
42 to 43
43 to 44
44 to 45
45 and over

years, 2024. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Boundaries: U.S. Census Bureau cartographic boundary files.

Top 40 counties, 2024

years. Source: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.

Full ranking

Rank	Counties	2024 years	Change on 2023
1	Pope County	54.2	0
2	Jo Daviess County	51.3	0
3	Henderson County	50.9	+0.1
4	Hardin County	50.6	-0.5
5	Alexander County	49.8	+0.8
6	Schuyler County	49.4	+0.5
7	Calhoun County	49.2	+0.2
8	Gallatin County	48	-0.2
9	Carroll County	46.8	+0.3
10	Putnam County	46.6	+0.2
11	Mason County	46.5	-0.1
12	Hancock County	46.3	+0.3
12	Scott County	46.3	-0.1
14	Marshall County	46	0
15	Shelby County	45.7	0
16	Edgar County	45.6	0
17	Massac County	45.3	+0.3
17	Stephenson County	45.3	-0.2
19	Bureau County	45.2	+0.1
20	Edwards County	44.9	+0.1
20	Macoupin County	44.9	+0.1
20	Mercer County	44.9	+0.1
20	Union County	44.9	-0.3
24	Jersey County	44.8	0
24	Pulaski County	44.8	+0.2
24	Washington County	44.8	0
27	Iroquois County	44.6	-0.1
28	Fulton County	44.5	0
29	Menard County	44.4	+0.2
30	Greene County	44.3	+0.3
30	Jasper County	44.3	+0.1
30	White County	44.3	0
33	Lee County	44.2	+0.2
34	Stark County	44.1	-0.3
35	Christian County	43.9	0
35	Franklin County	43.9	0
35	Henry County	43.9	+0.2
35	Monroe County	43.9	+0.4
39	Clark County	43.8	+0.2
39	Saline County	43.8	+0.2
41	Montgomery County	43.7	+0.2
41	Piatt County	43.7	+0.1
43	De Witt County	43.6	+0.2
43	Whiteside County	43.6	-0.1
45	Cumberland County	43.4	-0.1
45	Richland County	43.4	+0.2
47	Clay County	43.3	+0.3
47	Johnson County	43.3	+0.2
49	Knox County	43.2	0
49	Randolph County	43.2	+0.1
49	Wabash County	43.2	+0.2
52	LaSalle County	43	+0.2
52	Williamson County	43	+0.3
54	Crawford County	42.9	-0.4
54	Marion County	42.9	+0.3
56	Hamilton County	42.8	+0.4
56	Lawrence County	42.8	-0.1
56	Wayne County	42.8	-0.3
59	Jefferson County	42.6	+0.1
60	Ogle County	42.4	+0.1
60	Tazewell County	42.4	+0.1
62	Perry County	42.3	+0.2
63	Livingston County	42.2	-0.1
64	Ford County	42.1	-0.4
64	Pike County	42.1	+0.1
66	Adams County	42	+0.3
66	Morgan County	42	+0.3
66	Woodford County	42	+0.3
69	Logan County	41.9	0
70	Clinton County	41.8	+0.1
70	Macon County	41.8	+0.1
70	Sangamon County	41.8	+0.1
73	Moultrie County	41.5	+0.1
73	Vermilion County	41.5	0
75	Fayette County	41.4	-0.2
75	McHenry County	41.4	+0.2
75	Warren County	41.4	+0.1
78	Bond County	41.3	+0.1
79	Effingham County	41.1	+0.3
80	Madison County	40.9	+0.2
81	DuPage County	40.8	+0.1
82	Rock Island County	40.7	-0.3
83	Boone County	40.5	0
84	Brown County	40.3	+0.4
85	St. Clair County	40.2	+0.3
86	Kankakee County	40.1	+0.1
87	Winnebago County	40	0
88	Lake County	39.9	0
89	Cass County	39.7	+0.1
89	Will County	39.7	+0.2
91	Grundy County	39.4	+0.4
92	Kane County	39.2	+0.2
93	Douglas County	38.9	-0.2
94	Peoria County	38.7	+0.1
95	Coles County	38.2	+0.1
95	Cook County	38.2	0
97	McDonough County	36.6	+0.8
98	Kendall County	36.5	+0.2
99	McLean County	35.2	+0.1
100	DeKalb County	34	+0.1
101	Jackson County	32.8	-0.1
102	Champaign County	30.9	-0.1

Other periods

About this ranking

Age that divides the resident population of a US county into two halves of equal size on 1 July, from Census Bureau population estimates calculated by single year of age.

Counties only: the county file has no state or national medians, and medians cannot be added up. A single-year estimate, unlike median_age, which for US places is a five-year American Community Survey estimate.

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. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.

Citation styles

The publisher is the author. Invokely is named only as the place the figures were read, where a style asks for it.

APA 7

U.S. Census Bureau. (2026). Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage (Counties in Illinois by median age on 1 July (US county estimates), 2024) [Data set]. Retrieved October 12, 2026, from https://www.census.gov/programs-surveys/popest/data/data-sets.html

MLA 9

Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Illinois by median age on 1 July (US county estimates), 2024. U.S. Census Bureau, 25 June 2026, https://www.census.gov/programs-surveys/popest/data/data-sets.html. Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024. Accessed 12 Oct. 2026.

Chicago (author-date)

U.S. Census Bureau. 2026. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Counties in Illinois by median age on 1 July (US county estimates), 2024. Dataset. Accessed October 12, 2026. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Also distributed by Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024.

Harvard

U.S. Census Bureau (2026) Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage, Counties in Illinois by median age on 1 July (US county estimates), 2024 [Dataset]. Available at: https://www.census.gov/programs-surveys/popest/data/data-sets.html, via Invokely: https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024 (Accessed: 12 October 2026).

BibTeX

@misc{census_counties_in_illinois_by_2024,
  author = {{U.S. Census Bureau}},
  title = {{Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Illinois by median age on 1 July (US county estimates), 2024}},
  year = {2026},
  howpublished = {Data set},
  url = {https://www.census.gov/programs-surveys/popest/data/data-sets.html},
  urldate = {2026-10-12},
  note = {Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024. Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN\_AGE\_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.},
}

RIS

TY  - DATA
AU  - U.S. Census Bureau
TI  - Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage: Counties in Illinois by median age on 1 July (US county estimates), 2024
PY  - 2026
DA  - 2026/06/25
PB  - U.S. Census Bureau
DB  - Invokely
UR  - https://www.census.gov/programs-surveys/popest/data/data-sets.html
L2  - https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2024.
N1  - Publisher attribution: U.S. Census Bureau. Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. https://www.census.gov/programs-surveys/popest/data/data-sets.html. Retrieved 2026-10-12.
ER  -

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Rank Counties in Illinois by median age on 1 July (US county estimates) using official data, and cite the source.

rank_places {"indicator":"median_age_pep","level":"province","within":"Illinois","limit":10}
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Questions

Which county has the highest median age on 1 July (US county estimates)?

Pope County, with 54.2 years in 2024, according to the U.S. Census Bureau.

Which county has the lowest median age on 1 July (US county estimates)?

Champaign County, with 30.9 years in 2024.

Where does this ranking come from?

Every value comes from one source and one period, so the places are comparable: U.S. Census Bureau, Population Estimates Program, county population by age and sex: median age (MEDIAN_AGE_TOT) on 1 July, 2010 to 2019 from the 2010 to 2020 intercensal file and 2020 onwards from the latest vintage. Retrieved 2026-10-12.