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 2016, at 50.7 years. Champaign County had the lowest, at 30 years. The median was 42.6 years. Source: the U.S. Census Bureau.

Highest50.7Pope County

Lowest30Champaign County

Median42.6102 counties

Map of counties, 2016

Under 39
39 to 41
41 to 43
43 to 45
45 and over

years, 2016. 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, 2016

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	2016 years	Change on 2015
1	Pope County	50.7	+0.8
2	Hardin County	50	+0.7
3	Henderson County	49.6	+0.7
4	Jo Daviess County	49.2	+0.4
5	Calhoun County	47.3	0
6	Putnam County	47.1	+0.2
7	Carroll County	46.7	-0.3
7	Schuyler County	46.7	+0.7
9	Marshall County	45.8	-0.2
9	Mason County	45.8	+0.2
11	Hancock County	45.7	-0.4
12	Alexander County	45.6	+1.3
13	Mercer County	45.3	+0.3
14	Gallatin County	45.1	+0.3
14	Shelby County	45.1	+0.2
14	Stephenson County	45.1	0
17	White County	44.8	+0.2
18	Edgar County	44.5	+0.3
18	Stark County	44.5	-0.8
20	Union County	44.4	+0.1
21	Iroquois County	44.2	+0.3
21	Scott County	44.2	+0.6
23	Bureau County	44.1	-0.1
24	Pulaski County	43.9	-0.5
25	Jasper County	43.7	+0.2
25	Jersey County	43.7	+0.6
27	Edwards County	43.6	-0.2
27	Macoupin County	43.6	+0.1
27	Whiteside County	43.6	+0.3
30	Greene County	43.5	+0.5
30	Lee County	43.5	+0.1
30	Washington County	43.5	0
33	Massac County	43.4	+0.1
33	Menard County	43.4	-0.4
35	Clay County	43.3	+0.1
35	Johnson County	43.3	+0.6
35	Piatt County	43.3	-0.4
38	Franklin County	43.2	+0.4
38	Fulton County	43.2	0
40	Christian County	43.1	+0.1
40	Montgomery County	43.1	+0.2
40	Pike County	43.1	-0.3
43	Hamilton County	43	-0.2
44	De Witt County	42.9	-0.2
44	Ford County	42.9	0
46	Clark County	42.8	0
46	Richland County	42.8	-0.1
48	Cumberland County	42.7	+0.3
48	Knox County	42.7	+0.2
50	Crawford County	42.6	+0.1
50	Randolph County	42.6	+0.3
50	Wayne County	42.6	-0.2
53	Henry County	42.5	0
54	Monroe County	42.4	0
54	Saline County	42.4	+0.2
54	Wabash County	42.4	+0.2
57	Marion County	42.3	+0.2
58	LaSalle County	42.2	+0.2
59	Livingston County	42.1	+0.2
59	Ogle County	42.1	0
61	Morgan County	41.7	+0.1
62	Bond County	41.4	+0.1
62	Jefferson County	41.4	+0.2
64	Perry County	41.3	+0.2
65	Macon County	41.2	+0.3
66	Adams County	41.1	+0.1
66	Fayette County	41.1	+0.6
66	Logan County	41.1	+0.3
66	Williamson County	41.1	+0.2
70	Lawrence County	40.9	+0.2
70	Tazewell County	40.9	+0.2
72	Vermilion County	40.7	+0.2
73	Clinton County	40.6	+0.1
74	Moultrie County	40.5	+0.2
75	Warren County	40.4	+0.1
76	Woodford County	40.3	0
77	Rock Island County	40.2	+0.1
78	McHenry County	40.1	+0.2
78	Sangamon County	40.1	+0.2
80	Effingham County	39.8	0
81	Madison County	39.7	+0.1
82	Winnebago County	39.6	0
83	Douglas County	39.2	+0.1
83	DuPage County	39.2	+0.2
85	Brown County	39.1	+0.5
86	Boone County	39	+0.2
87	Cass County	38.9	-0.3
88	Kankakee County	38.4	+0.3
88	St. Clair County	38.4	+0.3
90	Lake County	38.3	+0.2
91	Will County	37.8	+0.3
92	Grundy County	37.6	+0.1
92	Peoria County	37.6	+0.3
94	Kane County	36.8	+0.3
95	Coles County	36.5	+0.7
95	Cook County	36.5	+0.2
97	Kendall County	34.7	+0.3
98	McDonough County	34.5	+1
99	McLean County	33.7	+0.3
100	Jackson County	32.8	+0.7
101	DeKalb County	32.7	+0.5
102	Champaign County	30	+0.2

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), 2016) [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), 2016. 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=2016. 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), 2016. 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=2016.

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), 2016 [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=2016 (Accessed: 12 October 2026).

BibTeX

@misc{census_counties_in_illinois_by_2016,
  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), 2016}},
  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=2016. 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), 2016
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=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/illinois-counties?period=2016.
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 50.7 years in 2016, according to the U.S. Census Bureau.

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

Champaign County, with 30 years in 2016.

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.