RANKING · 2025 ESTIMATES · 58 SHOWN OF 58

Most population lost, California counties

California counties that lost the most residents from the 2020 census to 2025, by raw count of people rather than percentage. This list covers the 58 counties in California that qualify, ranked against each other statewide. The median across all 58 is -391. Biggest climber in the top 100 since 2020: Los Angeles County, CA, up 55 places to #1.

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SAME RANKING BYCities States Metros

YEAR2000 2010 2020 2025

RANKPLACESTATEPOPPOPULATION CHANGEVS 2000

01▲55Los Angeles County, CACA9,694,934-319,075−149%

02▲44San Francisco County, CACA826,079-47,886−191%

03▲51Alameda County, CACA1,636,630-45,723−128%

04▲51Orange County, CACA3,149,507-37,482−109%

05▲47Santa Clara County, CACA1,914,391-21,868−112%

06▲38San Mateo County, CACA743,568-20,874−136%

07▲50San Diego County, CACA3,282,248-16,386−105%

08▲29Ventura County, CACA830,851-12,992−115%

09▲21Santa Cruz County, CACA258,852-12,009−146%

10▲23Marin County, CACA253,694-8,627−150%

11▲28Santa Barbara County, CACA442,065-6,164−121%

12▲26Monterey County, CACA433,729-5,306−112%

13▲4Napa County, CACA132,949-5,070−138%

14▲4Humboldt County, CACA131,647-4,816−165%

15▼13Lassen County, CACA28,117-4,613−174%

16▲8Mendocino County, CACA88,122-3,479−159%

17▼4Tuolumne County, CACA53,160-2,460−141%

18▼17Butte County, CACA209,211-2,421−112%

19▲8Sonoma County, CACA486,444-2,419−103%

20▼13Siskiyou County, CACA42,013-2,063−368%

21▼15Del Norte County, CACA26,410-1,333−133%

22▼12Plumas County, CACA18,583-1,207−211%

23▼3Tehama County, CACA64,665-1,164−118%

24▼9Inyo County, CACA18,158-858+155%

25Sutter County, CACA98,787-846−106%

26▼10Glenn County, CACA28,141-776−147%

27▼23Mono County, CACA12,505-690−124%

28▼2Shasta County, CACA181,648-507−103%

29▼10Trinity County, CACA15,720-392+856%

30▼7Lake County, CACA67,772-391−105%

31▼9Nevada County, CACA101,911-330−102%

32▼27Modoc County, CACA8,426-274+20%

33▼30Mariposa County, CACA16,918-213−108%

34▼22Alpine County, CACA1,043-161−269%

35▼24Sierra County, CACA3,098-138−158%

36▼1San Luis Obispo County, CACA282,367-57−100%

37▼23Colusa County, CACA21,836-3−100%

38▼4El Dorado County, CACA192,323+1,138−96%

39▼30Calaveras County, CACA46,605+1,313−85%

40▼19Amador County, CACA41,876+1,402−72%

41▼13Imperial County, CACA181,411+1,709−95%

42▼34Kings County, CACA154,327+1,841−93%

43Solano County, CACA455,376+1,885−97%

44▲6Contra Costa County, CACA1,170,070+4,143−97%

45▼3Stanislaus County, CACA557,719+4,841−94%

46▼15San Benito County, CACA70,082+5,873−64%

47▼15Yuba County, CACA88,691+7,116+257%

48▼12Yolo County, CACA224,410+8,007−71%

49▼20Madera County, CACA167,927+11,672−67%

50▼9Tulare County, CACA485,146+12,029−79%

51▼11Merced County, CACA297,260+16,058−50%

52▼5Kern County, CACA927,068+17,833−85%

53▼5Fresno County, CACA1,035,456+26,802−80%

54▼1Sacramento County, CACA1,618,460+33,405−82%

55▼10Placer County, CACA442,081+37,342−51%

56▼5San Bernardino County, CACA2,224,091+42,437−85%

57▼8San Joaquin County, CACA823,815+44,582−46%

58Riverside County, CACA2,544,916+126,731−66%

SHOWING 1–58 OF 58

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UPDATED 2026-09-11 · DATA: US CENSUS BUREAU POPULATION ESTIMATES