Data / Rankings / Median age on 1 July (US county estimates) / Counties in California

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

Sierra County had the highest median age on 1 July (US county estimates) of 58 counties in 2023, at 54.4 years. Yolo County had the lowest, at 32.1 years. The median was 39.9 years. Source: the U.S. Census Bureau.

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Highest54.4Sierra County
Lowest32.1Yolo County
Median39.958 counties

Map of counties, 2023

Alameda County: 38.9 yearsAlpine County: 51 yearsAmador County: 50.9 yearsButte County: 37.6 yearsCalaveras County: 50.5 yearsColusa County: 36 yearsContra Costa County: 40.8 yearsDel Norte County: 41.4 yearsEl Dorado County: 46.3 yearsFresno County: 33.7 yearsGlenn County: 38 yearsHumboldt County: 40 yearsImperial County: 34.3 yearsInyo County: 44.8 yearsKern County: 33.2 yearsKings County: 33.2 yearsLake County: 43.9 yearsLassen County: 38.4 yearsLos Angeles County: 38.4 yearsMadera County: 35 yearsMarin County: 47.5 yearsMariposa County: 50.5 yearsMendocino County: 44.2 yearsMerced County: 32.2 yearsModoc County: 48.8 yearsMono County: 40.7 yearsMonterey County: 36 yearsNapa County: 43.8 yearsNevada County: 49.3 yearsOrange County: 39.8 yearsPlacer County: 42.5 yearsPlumas County: 53.2 yearsRiverside County: 37.2 yearsSacramento County: 37.5 yearsSan Benito County: 37.1 yearsSan Bernardino County: 35.2 yearsSan Diego County: 37.6 yearsSan Francisco County: 39.8 yearsSan Joaquin County: 35.9 yearsSan Luis Obispo County: 41.6 yearsSan Mateo County: 41.1 yearsSanta Barbara County: 35.8 yearsSanta Clara County: 38.1 yearsSanta Cruz County: 40.8 yearsShasta County: 42.3 yearsSierra County: 54.4 yearsSiskiyou County: 48.3 yearsSolano County: 39.6 yearsSonoma County: 43.5 yearsStanislaus County: 35.6 yearsSutter County: 37.2 yearsTehama County: 40.2 yearsTrinity County: 48.8 yearsTulare County: 32.8 yearsTuolumne County: 48.1 yearsVentura County: 40.4 yearsYolo County: 32.1 yearsYuba County: 34.6 years
  • Under 35
  • 35 to 38
  • 38 to 40
  • 40 to 42
  • 42 to 48
  • 48 and over
years, 2023. 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.

All counties, 2023

Sierra County: 54.4 yearsSierra County54.4Plumas County: 53.2 yearsPlumas County53.2Alpine County: 51 yearsAlpine County51Amador County: 50.9 yearsAmador County50.9Calaveras County: 50.5 yearsCalaveras County50.5Mariposa County: 50.5 yearsMariposa County50.5Nevada County: 49.3 yearsNevada County49.3Modoc County: 48.8 yearsModoc County48.8Trinity County: 48.8 yearsTrinity County48.8Siskiyou County: 48.3 yearsSiskiyou County48.3Tuolumne County: 48.1 yearsTuolumne County48.1Marin County: 47.5 yearsMarin County47.5El Dorado County: 46.3 yearsEl Dorado County46.3Inyo County: 44.8 yearsInyo County44.8Mendocino County: 44.2 yearsMendocino County44.2Lake County: 43.9 yearsLake County43.9Napa County: 43.8 yearsNapa County43.8Sonoma County: 43.5 yearsSonoma County43.5Placer County: 42.5 yearsPlacer County42.5Shasta County: 42.3 yearsShasta County42.3San Luis Obispo County: 41.6 yearsSan Luis Obispo County41.6Del Norte County: 41.4 yearsDel Norte County41.4San Mateo County: 41.1 yearsSan Mateo County41.1Contra Costa County: 40.8 yearsContra Costa County40.8Santa Cruz County: 40.8 yearsSanta Cruz County40.8Mono County: 40.7 yearsMono County40.7Ventura County: 40.4 yearsVentura County40.4Tehama County: 40.2 yearsTehama County40.2Humboldt County: 40 yearsHumboldt County40Orange County: 39.8 yearsOrange County39.8San Francisco County: 39.8 yearsSan Francisco County39.8Solano County: 39.6 yearsSolano County39.6Alameda County: 38.9 yearsAlameda County38.9Lassen County: 38.4 yearsLassen County38.4Los Angeles County: 38.4 yearsLos Angeles County38.4Santa Clara County: 38.1 yearsSanta Clara County38.1Glenn County: 38 yearsGlenn County38Butte County: 37.6 yearsButte County37.6San Diego County: 37.6 yearsSan Diego County37.6Sacramento County: 37.5 yearsSacramento County37.5Riverside County: 37.2 yearsRiverside County37.2Sutter County: 37.2 yearsSutter County37.2San Benito County: 37.1 yearsSan Benito County37.1Colusa County: 36 yearsColusa County36Monterey County: 36 yearsMonterey County36San Joaquin County: 35.9 yearsSan Joaquin County35.9Santa Barbara County: 35.8 yearsSanta Barbara County35.8Stanislaus County: 35.6 yearsStanislaus County35.6San Bernardino County: 35.2 yearsSan Bernardino County35.2Madera County: 35 yearsMadera County35Yuba County: 34.6 yearsYuba County34.6Imperial County: 34.3 yearsImperial County34.3Fresno County: 33.7 yearsFresno County33.7Kern County: 33.2 yearsKern County33.2Kings County: 33.2 yearsKings County33.2Tulare County: 32.8 yearsTulare County32.8Merced County: 32.2 yearsMerced County32.2Yolo County: 32.1 yearsYolo County32.1Sierra County: 54.4 yearsSierra County54.4Plumas County: 53.2 yearsPlumas County53.2Alpine County: 51 yearsAlpine County51Amador County: 50.9 yearsAmador County50.9Calaveras County: 50.5 yearsCalaveras County50.5Mariposa County: 50.5 yearsMariposa County50.5Nevada County: 49.3 yearsNevada County49.3Modoc County: 48.8 yearsModoc County48.8Trinity County: 48.8 yearsTrinity County48.8Siskiyou County: 48.3 yearsSiskiyou County48.3Tuolumne County: 48.1 yearsTuolumne County48.1Marin County: 47.5 yearsMarin County47.5El Dorado County: 46.3 yearsEl Dorado County46.3Inyo County: 44.8 yearsInyo County44.8Mendocino County: 44.2 yearsMendocino County44.2Lake County: 43.9 yearsLake County43.9Napa County: 43.8 yearsNapa County43.8Sonoma County: 43.5 yearsSonoma County43.5Placer County: 42.5 yearsPlacer County42.5Shasta County: 42.3 yearsShasta County42.3San Luis Obispo County: 41.6 yearsSan Luis Obispo County41.6Del Norte County: 41.4 yearsDel Norte County41.4San Mateo County: 41.1 yearsSan Mateo County41.1Contra Costa County: 40.8 yearsContra Costa County40.8Santa Cruz County: 40.8 yearsSanta Cruz County40.8Mono County: 40.7 yearsMono County40.7Ventura County: 40.4 yearsVentura County40.4Tehama County: 40.2 yearsTehama County40.2Humboldt County: 40 yearsHumboldt County40Orange County: 39.8 yearsOrange County39.8San Francisco County: 39.8 yearsSan Francisco County39.8Solano County: 39.6 yearsSolano County39.6Alameda County: 38.9 yearsAlameda County38.9Lassen County: 38.4 yearsLassen County38.4Los Angeles County: 38.4 yearsLos Angeles County38.4Santa Clara County: 38.1 yearsSanta Clara County38.1Glenn County: 38 yearsGlenn County38Butte County: 37.6 yearsButte County37.6San Diego County: 37.6 yearsSan Diego County37.6Sacramento County: 37.5 yearsSacramento County37.5Riverside County: 37.2 yearsRiverside County37.2Sutter County: 37.2 yearsSutter County37.2San Benito County: 37.1 yearsSan Benito County37.1Colusa County: 36 yearsColusa County36Monterey County: 36 yearsMonterey County36San Joaquin County: 35.9 yearsSan Joaquin County35.9Santa Barbara County: 35.8 yearsSanta Barbara County35.8Stanislaus County: 35.6 yearsStanislaus County35.6San Bernardino County: 35.2 yearsSan Bernardino County35.2Madera County: 35 yearsMadera County35Yuba County: 34.6 yearsYuba County34.6Imperial County: 34.3 yearsImperial County34.3Fresno County: 33.7 yearsFresno County33.7Kern County: 33.2 yearsKern County33.2Kings County: 33.2 yearsKings County33.2Tulare County: 32.8 yearsTulare County32.8Merced County: 32.2 yearsMerced County32.2Yolo County: 32.1 yearsYolo County32.1
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

RankCounties2023
years		Change on 2022
1Sierra County54.4+0.1
2Plumas County53.20
3Alpine County510
4Amador County50.9-0.4
5Calaveras County50.5-0.1
5Mariposa County50.5-0.5
7Nevada County49.30
8Modoc County48.8-0.4
8Trinity County48.8+0.5
10Siskiyou County48.3+0.1
11Tuolumne County48.1-0.7
12Marin County47.5+0.3
13El Dorado County46.3+0.3
14Inyo County44.8+0.1
15Mendocino County44.2+0.3
16Lake County43.9-0.1
17Napa County43.8+0.4
18Sonoma County43.5+0.3
19Placer County42.5+0.1
20Shasta County42.30
21San Luis Obispo County41.6+0.1
22Del Norte County41.4+0.3
23San Mateo County41.1+0.2
24Contra Costa County40.8+0.2
24Santa Cruz County40.8+0.4
26Mono County40.70
27Ventura County40.4+0.3
28Tehama County40.20
29Humboldt County40+0.3
30Orange County39.8+0.3
30San Francisco County39.80
32Solano County39.6+0.2
33Alameda County38.9+0.2
34Lassen County38.4+0.6
34Los Angeles County38.4+0.2
36Santa Clara County38.10
37Glenn County38+0.3
38Butte County37.6+0.1
38San Diego County37.6+0.2
40Sacramento County37.5+0.1
41Riverside County37.2+0.2
41Sutter County37.2+0.1
43San Benito County37.1+0.3
44Colusa County360
44Monterey County36+0.3
46San Joaquin County35.9+0.3
47Santa Barbara County35.8+0.1
48Stanislaus County35.6+0.1
49San Bernardino County35.2+0.2
50Madera County35+0.2
51Yuba County34.6+0.1
52Imperial County34.3+0.2
53Fresno County33.7+0.1
54Kern County33.2+0.2
54Kings County33.2+0.2
56Tulare County32.8+0.3
57Merced County32.2+0.2
58Yolo County32.1+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 California by median age on 1 July (US county estimates), 2023) [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 California by median age on 1 July (US county estimates), 2023. 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/california-counties?period=2023. 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 California by median age on 1 July (US county estimates), 2023. 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/california-counties?period=2023.

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 California by median age on 1 July (US county estimates), 2023 [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/california-counties?period=2023 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2023,
  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 California by median age on 1 July (US county estimates), 2023}},
  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/california-counties?period=2023. 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 California by median age on 1 July (US county estimates), 2023
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/california-counties?period=2023
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/california-counties?period=2023.
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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Questions

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

Sierra County, with 54.4 years in 2023, according to the U.S. Census Bureau.

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

Yolo County, with 32.1 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, 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.

Median age on 1 July (US county estimates): other rankings

Counties in California: more rankings