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 2015, at 53.8 years. Tulare County had the lowest, at 31 years. The median was 37.9 years. Source: the U.S. Census Bureau.

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Highest53.8Sierra County
Lowest31Tulare County
Median37.958 counties

Map of counties, 2015

Alameda County: 36.9 yearsAlpine County: 49.8 yearsAmador County: 51.5 yearsButte County: 37.7 yearsCalaveras County: 51.7 yearsColusa County: 34.7 yearsContra Costa County: 39.2 yearsDel Norte County: 39.9 yearsEl Dorado County: 45.4 yearsFresno County: 32 yearsGlenn County: 37.1 yearsHumboldt County: 37.9 yearsImperial County: 33 yearsInyo County: 45.9 yearsKern County: 31.6 yearsKings County: 31.9 yearsLake County: 46.2 yearsLassen County: 37.6 yearsLos Angeles County: 36.1 yearsMadera County: 34 yearsMarin County: 45.6 yearsMariposa County: 52 yearsMendocino County: 42.6 yearsMerced County: 31 yearsModoc County: 48.3 yearsMono County: 38.8 yearsMonterey County: 33.7 yearsNapa County: 41 yearsNevada County: 49.3 yearsOrange County: 37.6 yearsPlacer County: 41.9 yearsPlumas County: 52.9 yearsRiverside County: 35.1 yearsSacramento County: 35.9 yearsSan Benito County: 35.8 yearsSan Bernardino County: 33.3 yearsSan Diego County: 35.6 yearsSan Francisco County: 38.2 yearsSan Joaquin County: 34.2 yearsSan Luis Obispo County: 40 yearsSan Mateo County: 39.4 yearsSanta Barbara County: 34.4 yearsSanta Clara County: 36.8 yearsSanta Cruz County: 38.2 yearsShasta County: 43 yearsSierra County: 53.8 yearsSiskiyou County: 48.1 yearsSolano County: 37.9 yearsSonoma County: 41.3 yearsStanislaus County: 34.4 yearsSutter County: 36.1 yearsTehama County: 40.7 yearsTrinity County: 49.8 yearsTulare County: 31 yearsTuolumne County: 49.2 yearsVentura County: 37.8 yearsYolo County: 32 yearsYuba County: 33.1 years
  • Under 34
  • 34 to 36
  • 36 to 38
  • 38 to 41
  • 41 to 48
  • 48 and over
years, 2015. 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, 2015

Sierra County: 53.8 yearsSierra County53.8Plumas County: 52.9 yearsPlumas County52.9Mariposa County: 52 yearsMariposa County52Calaveras County: 51.7 yearsCalaveras County51.7Amador County: 51.5 yearsAmador County51.5Alpine County: 49.8 yearsAlpine County49.8Trinity County: 49.8 yearsTrinity County49.8Nevada County: 49.3 yearsNevada County49.3Tuolumne County: 49.2 yearsTuolumne County49.2Modoc County: 48.3 yearsModoc County48.3Siskiyou County: 48.1 yearsSiskiyou County48.1Lake County: 46.2 yearsLake County46.2Inyo County: 45.9 yearsInyo County45.9Marin County: 45.6 yearsMarin County45.6El Dorado County: 45.4 yearsEl Dorado County45.4Shasta County: 43 yearsShasta County43Mendocino County: 42.6 yearsMendocino County42.6Placer County: 41.9 yearsPlacer County41.9Sonoma County: 41.3 yearsSonoma County41.3Napa County: 41 yearsNapa County41Tehama County: 40.7 yearsTehama County40.7San Luis Obispo County: 40 yearsSan Luis Obispo County40Del Norte County: 39.9 yearsDel Norte County39.9San Mateo County: 39.4 yearsSan Mateo County39.4Contra Costa County: 39.2 yearsContra Costa County39.2Mono County: 38.8 yearsMono County38.8San Francisco County: 38.2 yearsSan Francisco County38.2Santa Cruz County: 38.2 yearsSanta Cruz County38.2Humboldt County: 37.9 yearsHumboldt County37.9Solano County: 37.9 yearsSolano County37.9Ventura County: 37.8 yearsVentura County37.8Butte County: 37.7 yearsButte County37.7Lassen County: 37.6 yearsLassen County37.6Orange County: 37.6 yearsOrange County37.6Glenn County: 37.1 yearsGlenn County37.1Alameda County: 36.9 yearsAlameda County36.9Santa Clara County: 36.8 yearsSanta Clara County36.8Los Angeles County: 36.1 yearsLos Angeles County36.1Sutter County: 36.1 yearsSutter County36.1Sacramento County: 35.9 yearsSacramento County35.9San Benito County: 35.8 yearsSan Benito County35.8San Diego County: 35.6 yearsSan Diego County35.6Riverside County: 35.1 yearsRiverside County35.1Colusa County: 34.7 yearsColusa County34.7Santa Barbara County: 34.4 yearsSanta Barbara County34.4Stanislaus County: 34.4 yearsStanislaus County34.4San Joaquin County: 34.2 yearsSan Joaquin County34.2Madera County: 34 yearsMadera County34Monterey County: 33.7 yearsMonterey County33.7San Bernardino County: 33.3 yearsSan Bernardino County33.3Yuba County: 33.1 yearsYuba County33.1Imperial County: 33 yearsImperial County33Fresno County: 32 yearsFresno County32Yolo County: 32 yearsYolo County32Kings County: 31.9 yearsKings County31.9Kern County: 31.6 yearsKern County31.6Merced County: 31 yearsMerced County31Tulare County: 31 yearsTulare County31Sierra County: 53.8 yearsSierra County53.8Plumas County: 52.9 yearsPlumas County52.9Mariposa County: 52 yearsMariposa County52Calaveras County: 51.7 yearsCalaveras County51.7Amador County: 51.5 yearsAmador County51.5Alpine County: 49.8 yearsAlpine County49.8Trinity County: 49.8 yearsTrinity County49.8Nevada County: 49.3 yearsNevada County49.3Tuolumne County: 49.2 yearsTuolumne County49.2Modoc County: 48.3 yearsModoc County48.3Siskiyou County: 48.1 yearsSiskiyou County48.1Lake County: 46.2 yearsLake County46.2Inyo County: 45.9 yearsInyo County45.9Marin County: 45.6 yearsMarin County45.6El Dorado County: 45.4 yearsEl Dorado County45.4Shasta County: 43 yearsShasta County43Mendocino County: 42.6 yearsMendocino County42.6Placer County: 41.9 yearsPlacer County41.9Sonoma County: 41.3 yearsSonoma County41.3Napa County: 41 yearsNapa County41Tehama County: 40.7 yearsTehama County40.7San Luis Obispo County: 40 yearsSan Luis Obispo County40Del Norte County: 39.9 yearsDel Norte County39.9San Mateo County: 39.4 yearsSan Mateo County39.4Contra Costa County: 39.2 yearsContra Costa County39.2Mono County: 38.8 yearsMono County38.8San Francisco County: 38.2 yearsSan Francisco County38.2Santa Cruz County: 38.2 yearsSanta Cruz County38.2Humboldt County: 37.9 yearsHumboldt County37.9Solano County: 37.9 yearsSolano County37.9Ventura County: 37.8 yearsVentura County37.8Butte County: 37.7 yearsButte County37.7Lassen County: 37.6 yearsLassen County37.6Orange County: 37.6 yearsOrange County37.6Glenn County: 37.1 yearsGlenn County37.1Alameda County: 36.9 yearsAlameda County36.9Santa Clara County: 36.8 yearsSanta Clara County36.8Los Angeles County: 36.1 yearsLos Angeles County36.1Sutter County: 36.1 yearsSutter County36.1Sacramento County: 35.9 yearsSacramento County35.9San Benito County: 35.8 yearsSan Benito County35.8San Diego County: 35.6 yearsSan Diego County35.6Riverside County: 35.1 yearsRiverside County35.1Colusa County: 34.7 yearsColusa County34.7Santa Barbara County: 34.4 yearsSanta Barbara County34.4Stanislaus County: 34.4 yearsStanislaus County34.4San Joaquin County: 34.2 yearsSan Joaquin County34.2Madera County: 34 yearsMadera County34Monterey County: 33.7 yearsMonterey County33.7San Bernardino County: 33.3 yearsSan Bernardino County33.3Yuba County: 33.1 yearsYuba County33.1Imperial County: 33 yearsImperial County33Fresno County: 32 yearsFresno County32Yolo County: 32 yearsYolo County32Kings County: 31.9 yearsKings County31.9Kern County: 31.6 yearsKern County31.6Merced County: 31 yearsMerced County31Tulare County: 31 yearsTulare County31
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

RankCounties2015
years		Change on 2014
1Sierra County53.80
2Plumas County52.9+0.7
3Mariposa County52+0.3
4Calaveras County51.7+0.4
5Amador County51.5+0.3
6Alpine County49.8-0.3
6Trinity County49.8-0.4
8Nevada County49.3+0.2
9Tuolumne County49.2+0.5
10Modoc County48.3+0.2
11Siskiyou County48.10
12Lake County46.2+0.2
13Inyo County45.9+0.3
14Marin County45.6+0.3
15El Dorado County45.4+0.2
16Shasta County43+0.2
17Mendocino County42.6+0.2
18Placer County41.9+0.3
19Sonoma County41.3+0.2
20Napa County41+0.2
21Tehama County40.70
22San Luis Obispo County40+0.3
23Del Norte County39.9+0.3
24San Mateo County39.4-0.1
25Contra Costa County39.2+0.1
26Mono County38.8+0.7
27San Francisco County38.2-0.2
27Santa Cruz County38.2+0.3
29Humboldt County37.9+0.2
29Solano County37.9+0.2
31Ventura County37.8+0.3
32Butte County37.7+0.2
33Lassen County37.6-0.1
33Orange County37.6+0.3
35Glenn County37.1+0.3
36Alameda County36.90
37Santa Clara County36.80
38Los Angeles County36.1+0.3
38Sutter County36.1+0.3
40Sacramento County35.9+0.2
41San Benito County35.8+0.4
42San Diego County35.6+0.3
43Riverside County35.1+0.3
44Colusa County34.7+0.4
45Santa Barbara County34.4+0.2
45Stanislaus County34.4+0.2
47San Joaquin County34.2+0.2
48Madera County34+0.2
49Monterey County33.7+0.1
50San Bernardino County33.3+0.3
51Yuba County33.1+0.3
52Imperial County33+0.3
53Fresno County32+0.2
53Yolo County32+0.2
55Kings County31.9+0.2
56Kern County31.6+0.2
57Merced County31+0.3
57Tulare County31+0.3

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), 2015) [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), 2015. 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=2015. 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), 2015. 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=2015.

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), 2015 [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=2015 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_by_2015,
  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), 2015}},
  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=2015. 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), 2015
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=2015
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/california-counties?period=2015.
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 53.8 years in 2015, according to the U.S. Census Bureau.

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

Tulare County, with 31 years in 2015.

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