Counties in California by median age, 2024

Name: Counties in California by median age, 2024
Creator: U.S. Census Bureau
License: Public domain (US federal government work, citation requested)

Trinity County had the highest median age of 58 counties in 2024, at 54.9 years. Merced County had the lowest, at 31.8 years. The median was 39.7 years and the figure for California was 37.9 years. Source: the U.S. Census Bureau.

Highest54.9Trinity County

Lowest31.8Merced County

Median39.758 counties

California37.9History

All counties, 2024

CSV Chart (SVG)

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

Full ranking

Rank	Counties	2024 years	Change on 2023
1	Trinity County	54.9	+0.1
2	Sierra County	54.7	-1.3
3	Calaveras County	52	0
3	Plumas County	52	-0.1
5	Mariposa County	51.2	-0.4
6	Nevada County	50.1	-0.2
7	Amador County	49.7	-0.2
8	Tuolumne County	48.4	-0.4
9	Modoc County	47.5	-1.5
10	Marin County	47.4	+0.1
11	Siskiyou County	47.2	-0.2
12	El Dorado County	46.1	0
13	Inyo County	45.5	-0.1
14	Lake County	44.1	-0.1
14	Mendocino County	44.1	+0.2
16	Napa County	42.9	+0.1
16	Sonoma County	42.9	+0.2
18	Placer County	42.5	+0.1
19	Shasta County	41.7	0
20	Mono County	41.5	+1.2
21	San Mateo County	40.9	+0.3
22	Contra Costa County	40.5	+0.2
23	San Luis Obispo County	40.4	+0.2
24	San Francisco County	40	+0.3
24	Tehama County	40	-0.1
26	Del Norte County	39.9	-0.9
26	Humboldt County	39.9	+0.3
28	Alpine County	39.8	-1.3
28	Santa Cruz County	39.8	+0.2
30	Ventura County	39.6	+0.2
31	Orange County	39.4	+0.3
32	Solano County	39.2	+0.1
33	Alameda County	39	+0.3
34	Lassen County	38.3	+0.5
35	Los Angeles County	38.2	+0.3
36	Santa Clara County	38.1	+0.2
37	Sacramento County	37.5	+0.3
38	San Diego County	37.3	+0.2
39	Riverside County	37	+0.3
40	Sutter County	36.5	+0.1
41	Butte County	36.2	-0.1
41	Glenn County	36.2	+0.3
43	San Benito County	36.1	+0.2
44	Colusa County	35.9	+0.2
45	Monterey County	35.5	+0.2
46	San Joaquin County	35.4	+0.2
47	Stanislaus County	34.9	+0.1
48	San Bernardino County	34.7	+0.3
49	Madera County	34.6	0
49	Santa Barbara County	34.6	+0.1
51	Yuba County	34.2	+0.3
52	Fresno County	33.5	+0.3
53	Imperial County	33.2	+0.2
54	Kern County	32.7	+0.3
55	Kings County	32.5	+0.2
56	Tulare County	32.1	+0.2
56	Yolo County	32.1	-0.2
58	Merced County	31.8	0

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/2024/table-based-SF/data/5YRData/acsdt5y2024-b01002.dat. Retrieved 2026-10-08.

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Questions

Which county has the highest median age?

Trinity County, with 54.9 years in 2024, according to the U.S. Census Bureau.

Which county has the lowest median age?

Merced County, with 31.8 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, American Community Survey 5-year estimates, table B01002: median age, total population. Retrieved 2026-10-08.