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 2016, at 54.6 years. Merced County had the lowest, at 31.2 years. The median was 38 years. Source: the U.S. Census Bureau.

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Highest54.6Sierra County
Lowest31.2Merced County
Median3858 counties

Map of counties, 2016

Alameda County: 37 yearsAlpine County: 51.5 yearsAmador County: 51.6 yearsButte County: 37.8 yearsCalaveras County: 51.7 yearsColusa County: 34.8 yearsContra Costa County: 39.3 yearsDel Norte County: 39.8 yearsEl Dorado County: 45.9 yearsFresno County: 32.2 yearsGlenn County: 37.2 yearsHumboldt County: 37.9 yearsImperial County: 33.3 yearsInyo County: 45.8 yearsKern County: 31.8 yearsKings County: 32.1 yearsLake County: 46.2 yearsLassen County: 37.4 yearsLos Angeles County: 36.4 yearsMadera County: 34.2 yearsMarin County: 45.8 yearsMariposa County: 52.1 yearsMendocino County: 42.7 yearsMerced County: 31.2 yearsModoc County: 47.9 yearsMono County: 39 yearsMonterey County: 34 yearsNapa County: 41.5 yearsNevada County: 49.6 yearsOrange County: 37.9 yearsPlacer County: 42 yearsPlumas County: 52.7 yearsRiverside County: 35.5 yearsSacramento County: 36.1 yearsSan Benito County: 36 yearsSan Bernardino County: 33.6 yearsSan Diego County: 35.9 yearsSan Francisco County: 38 yearsSan Joaquin County: 34.5 yearsSan Luis Obispo County: 40.2 yearsSan Mateo County: 39.4 yearsSanta Barbara County: 34.6 yearsSanta Clara County: 36.9 yearsSanta Cruz County: 38.5 yearsShasta County: 43.1 yearsSierra County: 54.6 yearsSiskiyou County: 47.8 yearsSolano County: 38 yearsSonoma County: 41.5 yearsStanislaus County: 34.6 yearsSutter County: 36.2 yearsTehama County: 40.6 yearsTrinity County: 49.5 yearsTulare County: 31.3 yearsTuolumne County: 49.2 yearsVentura County: 38.1 yearsYolo County: 32 yearsYuba County: 33.5 years
  • Under 34
  • 34 to 36
  • 36 to 38
  • 38 to 42
  • 42 to 48
  • 48 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.

All counties, 2016

Sierra County: 54.6 yearsSierra County54.6Plumas County: 52.7 yearsPlumas County52.7Mariposa County: 52.1 yearsMariposa County52.1Calaveras County: 51.7 yearsCalaveras County51.7Amador County: 51.6 yearsAmador County51.6Alpine County: 51.5 yearsAlpine County51.5Nevada County: 49.6 yearsNevada County49.6Trinity County: 49.5 yearsTrinity County49.5Tuolumne County: 49.2 yearsTuolumne County49.2Modoc County: 47.9 yearsModoc County47.9Siskiyou County: 47.8 yearsSiskiyou County47.8Lake County: 46.2 yearsLake County46.2El Dorado County: 45.9 yearsEl Dorado County45.9Inyo County: 45.8 yearsInyo County45.8Marin County: 45.8 yearsMarin County45.8Shasta County: 43.1 yearsShasta County43.1Mendocino County: 42.7 yearsMendocino County42.7Placer County: 42 yearsPlacer County42Napa County: 41.5 yearsNapa County41.5Sonoma County: 41.5 yearsSonoma County41.5Tehama County: 40.6 yearsTehama County40.6San Luis Obispo County: 40.2 yearsSan Luis Obispo County40.2Del Norte County: 39.8 yearsDel Norte County39.8San Mateo County: 39.4 yearsSan Mateo County39.4Contra Costa County: 39.3 yearsContra Costa County39.3Mono County: 39 yearsMono County39Santa Cruz County: 38.5 yearsSanta Cruz County38.5Ventura County: 38.1 yearsVentura County38.1San Francisco County: 38 yearsSan Francisco County38Solano County: 38 yearsSolano County38Humboldt County: 37.9 yearsHumboldt County37.9Orange County: 37.9 yearsOrange County37.9Butte County: 37.8 yearsButte County37.8Lassen County: 37.4 yearsLassen County37.4Glenn County: 37.2 yearsGlenn County37.2Alameda County: 37 yearsAlameda County37Santa Clara County: 36.9 yearsSanta Clara County36.9Los Angeles County: 36.4 yearsLos Angeles County36.4Sutter County: 36.2 yearsSutter County36.2Sacramento County: 36.1 yearsSacramento County36.1San Benito County: 36 yearsSan Benito County36San Diego County: 35.9 yearsSan Diego County35.9Riverside County: 35.5 yearsRiverside County35.5Colusa County: 34.8 yearsColusa County34.8Santa Barbara County: 34.6 yearsSanta Barbara County34.6Stanislaus County: 34.6 yearsStanislaus County34.6San Joaquin County: 34.5 yearsSan Joaquin County34.5Madera County: 34.2 yearsMadera County34.2Monterey County: 34 yearsMonterey County34San Bernardino County: 33.6 yearsSan Bernardino County33.6Yuba County: 33.5 yearsYuba County33.5Imperial County: 33.3 yearsImperial County33.3Fresno County: 32.2 yearsFresno County32.2Kings County: 32.1 yearsKings County32.1Yolo County: 32 yearsYolo County32Kern County: 31.8 yearsKern County31.8Tulare County: 31.3 yearsTulare County31.3Merced County: 31.2 yearsMerced County31.2Sierra County: 54.6 yearsSierra County54.6Plumas County: 52.7 yearsPlumas County52.7Mariposa County: 52.1 yearsMariposa County52.1Calaveras County: 51.7 yearsCalaveras County51.7Amador County: 51.6 yearsAmador County51.6Alpine County: 51.5 yearsAlpine County51.5Nevada County: 49.6 yearsNevada County49.6Trinity County: 49.5 yearsTrinity County49.5Tuolumne County: 49.2 yearsTuolumne County49.2Modoc County: 47.9 yearsModoc County47.9Siskiyou County: 47.8 yearsSiskiyou County47.8Lake County: 46.2 yearsLake County46.2El Dorado County: 45.9 yearsEl Dorado County45.9Inyo County: 45.8 yearsInyo County45.8Marin County: 45.8 yearsMarin County45.8Shasta County: 43.1 yearsShasta County43.1Mendocino County: 42.7 yearsMendocino County42.7Placer County: 42 yearsPlacer County42Napa County: 41.5 yearsNapa County41.5Sonoma County: 41.5 yearsSonoma County41.5Tehama County: 40.6 yearsTehama County40.6San Luis Obispo County: 40.2 yearsSan Luis Obispo County40.2Del Norte County: 39.8 yearsDel Norte County39.8San Mateo County: 39.4 yearsSan Mateo County39.4Contra Costa County: 39.3 yearsContra Costa County39.3Mono County: 39 yearsMono County39Santa Cruz County: 38.5 yearsSanta Cruz County38.5Ventura County: 38.1 yearsVentura County38.1San Francisco County: 38 yearsSan Francisco County38Solano County: 38 yearsSolano County38Humboldt County: 37.9 yearsHumboldt County37.9Orange County: 37.9 yearsOrange County37.9Butte County: 37.8 yearsButte County37.8Lassen County: 37.4 yearsLassen County37.4Glenn County: 37.2 yearsGlenn County37.2Alameda County: 37 yearsAlameda County37Santa Clara County: 36.9 yearsSanta Clara County36.9Los Angeles County: 36.4 yearsLos Angeles County36.4Sutter County: 36.2 yearsSutter County36.2Sacramento County: 36.1 yearsSacramento County36.1San Benito County: 36 yearsSan Benito County36San Diego County: 35.9 yearsSan Diego County35.9Riverside County: 35.5 yearsRiverside County35.5Colusa County: 34.8 yearsColusa County34.8Santa Barbara County: 34.6 yearsSanta Barbara County34.6Stanislaus County: 34.6 yearsStanislaus County34.6San Joaquin County: 34.5 yearsSan Joaquin County34.5Madera County: 34.2 yearsMadera County34.2Monterey County: 34 yearsMonterey County34San Bernardino County: 33.6 yearsSan Bernardino County33.6Yuba County: 33.5 yearsYuba County33.5Imperial County: 33.3 yearsImperial County33.3Fresno County: 32.2 yearsFresno County32.2Kings County: 32.1 yearsKings County32.1Yolo County: 32 yearsYolo County32Kern County: 31.8 yearsKern County31.8Tulare County: 31.3 yearsTulare County31.3Merced County: 31.2 yearsMerced County31.2
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

RankCounties2016
years		Change on 2015
1Sierra County54.6+0.8
2Plumas County52.7-0.2
3Mariposa County52.1+0.1
4Calaveras County51.70
5Amador County51.6+0.1
6Alpine County51.5+1.7
7Nevada County49.6+0.3
8Trinity County49.5-0.3
9Tuolumne County49.20
10Modoc County47.9-0.4
11Siskiyou County47.8-0.3
12Lake County46.20
13El Dorado County45.9+0.5
14Inyo County45.8-0.1
14Marin County45.8+0.2
16Shasta County43.1+0.1
17Mendocino County42.7+0.1
18Placer County42+0.1
19Napa County41.5+0.5
19Sonoma County41.5+0.2
21Tehama County40.6-0.1
22San Luis Obispo County40.2+0.2
23Del Norte County39.8-0.1
24San Mateo County39.40
25Contra Costa County39.3+0.1
26Mono County39+0.2
27Santa Cruz County38.5+0.3
28Ventura County38.1+0.3
29San Francisco County38-0.2
29Solano County38+0.1
31Humboldt County37.90
31Orange County37.9+0.3
33Butte County37.8+0.1
34Lassen County37.4-0.2
35Glenn County37.2+0.1
36Alameda County37+0.1
37Santa Clara County36.9+0.1
38Los Angeles County36.4+0.3
39Sutter County36.2+0.1
40Sacramento County36.1+0.2
41San Benito County36+0.2
42San Diego County35.9+0.3
43Riverside County35.5+0.4
44Colusa County34.8+0.1
45Santa Barbara County34.6+0.2
45Stanislaus County34.6+0.2
47San Joaquin County34.5+0.3
48Madera County34.2+0.2
49Monterey County34+0.3
50San Bernardino County33.6+0.3
51Yuba County33.5+0.4
52Imperial County33.3+0.3
53Fresno County32.2+0.2
54Kings County32.1+0.2
55Yolo County320
56Kern County31.8+0.2
57Tulare County31.3+0.3
58Merced County31.2+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 California 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 California 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/california-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 California 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/california-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 California 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/california-counties?period=2016 (Accessed: 12 October 2026).

BibTeX
@misc{census_counties_in_california_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 California 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/california-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 California 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/california-counties?period=2016
Y2  - 2026/10/12
N1  - Accessed via Invokely, https://invokely.ai/rankings/median-age-july-1-us-counties/california-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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Questions

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

Sierra County, with 54.6 years in 2016, according to the U.S. Census Bureau.

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

Merced County, with 31.2 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.

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

Counties in California: more rankings