RANKING · 2010 CENSUS · 58 SHOWN OF 58

Oldest by median age, California counties · 2010

California counties ranked by median age of residents (2010 ACS). This list covers the 58 counties in California that qualify, ranked against each other statewide. The median across all 58 is 37.1.

Flip the list · Youngest by median age, US counties →

CaliforniaAll states All rankings

SAME RANKING BYCities States Metros ZIP codes

YEAR1990 2000 2010 2020 2024

RANKPLACESTATEPOPMEDIAN AGEVS 2000

01Sierra County, CACA3,09850.9+16%

02Plumas County, CACA18,58349.6+12%

03Trinity County, CACA15,72049.3+11%

04Calaveras County, CACA46,60549.2+10%

05Mariposa County, CACA16,91849.2+15%

06Amador County, CACA41,87648.2+13%

07Nevada County, CACA101,91147.6+10%

08Tuolumne County, CACA53,16047.3+10%

09Siskiyou County, CACA42,01347.0+9%

10Alpine County, CACA1,04346.7+19%

11Modoc County, CACA8,42646.1+10%

12Inyo County, CACA18,15845.6+7%

13Lake County, CACA67,77245.0+5%

14Marin County, CACA253,69444.5+8%

15El Dorado County, CACA192,32343.6+11%

16Shasta County, CACA181,64841.8+7%

17Mendocino County, CACA88,12241.5+7%

18Placer County, CACA442,08140.3+6%

19Sonoma County, CACA486,44439.9+6%

20Napa County, CACA132,94939.7+4%

21Tehama County, CACA64,66539.5+4%

22San Luis Obispo County, CACA282,36739.4+6%

23San Mateo County, CACA743,56839.3+7%

24Del Norte County, CACA26,41039.1+7%

25Contra Costa County, CACA1,170,07038.5+6%

26San Francisco County, CACA826,07938.5+5%

27Butte County, CACA209,21137.2+4%

28Mono County, CACA12,50537.2+3%

29Humboldt County, CACA131,64737.1+2%

30Lassen County, CACA28,11737.1+7%

31Santa Cruz County, CACA258,85236.9+5%

32Solano County, CACA455,37636.9+9%

33Alameda County, CACA1,636,63036.6+6%

34Orange County, CACA3,149,50736.2+9%

35Santa Clara County, CACA1,914,39136.2+6%

36Ventura County, CACA830,85136.2+6%

37Glenn County, CACA28,14135.3+5%

38Los Angeles County, CACA9,694,93434.8+9%

39Sacramento County, CACA1,618,46034.8+3%

40San Diego County, CACA3,282,24834.6+4%

41Sutter County, CACA98,78734.5+1%

42San Benito County, CACA70,08234.3+9%

43Riverside County, CACA2,544,91633.7+2%

44Santa Barbara County, CACA442,06533.6+1%

45Colusa County, CACA21,83633.5+6%

46Madera County, CACA167,92733.0+1%

47Monterey County, CACA433,72932.9+4%

48Stanislaus County, CACA557,71932.9+4%

49San Joaquin County, CACA823,81532.7+3%

50Yuba County, CACA88,69132.1+2%

51Imperial County, CACA181,41131.9+3%

52San Bernardino County, CACA2,224,09131.7+5%

53Kings County, CACA154,32731.1+3%

54Kern County, CACA927,06830.70%

55Fresno County, CACA1,035,45630.6+2%

56Yolo County, CACA224,41030.4+3%

57Merced County, CACA297,26029.6+2%

58Tulare County, CACA485,14629.6+1%

SHOWING 1–58 OF 58

Download CSV (full list, 58 rows)

UPDATED 2026-09-11 · DATA: US CENSUS BUREAU DECENNIAL CENSUS