Counties in Idaho by median age

Name: Counties in Idaho by median age, 2023
Creator: U.S. Census Bureau
License: Public domain (US federal government work, citation requested)

Custer County had the highest median age of 44 counties in 2023, at 59.5 years. Madison County had the lowest, at 21.4 years. The median was 39 years and the figure for Idaho was 37.1 years. Source: the U.S. Census Bureau.

Highest59.5Custer County

Lowest21.4Madison County

Median3944 counties

Idaho37.1History

All counties, 2023

CSV Chart (SVG)

years. Source: U.S. Census Bureau. Retrieved 2026-10-08.

Full ranking

Rank	Counties	2023 years	Change on 2022
1	Custer County	59.5	+4
2	Adams County	54.3	-0.1
3	Boise County	53.5	-0.2
4	Lemhi County	53.1	-0.1
5	Clearwater County	52	-0.3
6	Idaho County	49.6	+0.1
7	Valley County	49	+0.1
8	Lewis County	48.9	-0.2
9	Bonner County	48.2	-0.1
10	Benewah County	46	+0.1
11	Blaine County	45.5	+1
12	Shoshone County	45.1	-1
13	Washington County	44.6	-0.1
14	Boundary County	42.8	-0.8
14	Gem County	42.8	-1.2
16	Nez Perce County	40.9	+0.2
17	Kootenai County	40.8	+0.1
18	Bear Lake County	40.2	+0.2
18	Oneida County	40.2	+0.5
20	Fremont County	39.9	+0.9
21	Teton County	39.8	+1.2
22	Butte County	39.2	-3.9
23	Payette County	38.8	-1.2
24	Gooding County	38.4	+0.1
25	Ada County	38.3	+0.2
25	Owyhee County	38.3	-0.6
27	Caribou County	38	+0.1
28	Lincoln County	37.2	-0.1
29	Twin Falls County	35.8	+0.3
30	Bannock County	35	+0.3
31	Camas County	34.9	-1.6
32	Bingham County	34.8	+0.5
32	Canyon County	34.8	+0.4
34	Minidoka County	34.5	-0.4
35	Power County	33.9	-1.4
36	Jerome County	33.6	+0.6
37	Clark County	33.4	-4.2
38	Bonneville County	33.3	+0.1
39	Cassia County	33.1	0
40	Elmore County	32.5	+0.2
40	Franklin County	32.5	-0.1
42	Jefferson County	32.3	+0.6
43	Latah County	30.7	+0.4
44	Madison County	21.4	-0.2

Other periods

2024
2023
2022
2021

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 Idaho by median age using official data, and cite the source.

rank_places {"indicator":"median_age","level":"province","within":"Idaho","limit":10}
GET https://invokely.ai/api/v1/rank?indicator=median_age&level=province&within=Idaho&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?

Custer County, with 59.5 years in 2023, according to the U.S. Census Bureau.

Which county has the lowest median age?

Madison County, with 21.4 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.