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California by county: Census 2020–2024

Every adult in California, as the Census counts them, county by county and grouped by metro area. Each person is a real combination of traits from the Census's anonymised person records, weighted so every county matches its published tables, with party lean and 2024 turnout modelled and labelled so.

58 places, by metro area / county · Team plan

Every plan can look; creating a population from a state by county or by município needs Team.

What each person has

County by county

Adults in each county: darker has more. Point at a county for its numbers.

San Joaquin County: 588,510 adults (1.9%)Imperial County: 129,148 adults (0.4%)Shasta County: 142,288 adults (0.5%)Humboldt County: 109,240 adults (0.4%)Orange County: 2,500,687 adults (8.2%)Trinity County: 13,133 adults (0.0%)Monterey County: 325,339 adults (1.1%)Amador County: 35,039 adults (0.1%)Merced County: 206,871 adults (0.7%)San Bernardino County: 1,636,726 adults (5.3%)Ventura County: 654,762 adults (2.1%)Yolo County: 176,281 adults (0.6%)Marin County: 207,983 adults (0.7%)Inyo County: 14,958 adults (0.0%)Alameda County: 1,323,197 adults (4.3%)Siskiyou County: 34,776 adults (0.1%)Mendocino County: 71,347 adults (0.2%)El Dorado County: 155,029 adults (0.5%)Mariposa County: 14,141 adults (0.0%)Nevada County: 85,070 adults (0.3%)Santa Cruz County: 216,213 adults (0.7%)San Francisco County: 716,727 adults (2.3%)Napa County: 108,643 adults (0.4%)Plumas County: 16,087 adults (0.1%)Santa Clara County: 1,511,971 adults (4.9%)Modoc County: 6,961 adults (0.0%)Fresno County: 734,206 adults (2.4%)Tehama County: 49,471 adults (0.2%)Sonoma County: 392,643 adults (1.3%)Tulare County: 336,272 adults (1.1%)Mono County: 10,819 adults (0.0%)Tuolumne County: 45,193 adults (0.1%)Solano County: 353,088 adults (1.2%)Stanislaus County: 406,611 adults (1.3%)Calaveras County: 38,415 adults (0.1%)Riverside County: 1,881,231 adults (6.1%)Yuba County: 61,543 adults (0.2%)Del Norte County: 21,450 adults (0.1%)Sacramento County: 1,229,481 adults (4.0%)Santa Barbara County: 344,302 adults (1.1%)Lake County: 53,218 adults (0.2%)Madera County: 117,268 adults (0.4%)Lassen County: 24,745 adults (0.1%)San Mateo County: 597,245 adults (1.9%)Kings County: 112,172 adults (0.4%)San Diego County: 2,601,457 adults (8.5%)Placer County: 327,869 adults (1.1%)Butte County: 165,477 adults (0.5%)Kern County: 653,585 adults (2.1%)Colusa County: 16,070 adults (0.1%)Sierra County: 2,349 adults (0.0%)San Benito County: 50,274 adults (0.2%)Alpine County: 1,295 adults (0.0%)San Luis Obispo County: 232,311 adults (0.8%)Los Angeles County: 7,789,527 adults (25.4%)Sutter County: 73,983 adults (0.2%)Glenn County: 20,872 adults (0.1%)Contra Costa County: 909,012 adults (3.0%)
1,2957,789,527adults, on a log scale

Error report

How close these people come to the published figures, and where they fall short.

30,654,581 adults · 1,514,829 Census records · 58 counties in 26 areas (metro areas and the rest of the state)

Built 2026-10-09 · records california-2024-v1

How close the people land on the Census

Each county's records are weighted until they match its American Community Survey tables. The figure is the worst county's largest gap on each table, in percentage points.

TableWorst county
Sex by age0.5
Race and ethnicity0.5
Education0.4
Household income0.5
Work0.4
Owned or rented home0.2
Citizenship0.0

A check left out of the fit: veterans

Veteran status was not used in weighting, so it shows how well the weighted people carry traits nobody fitted. Per county, the share of veterans among civilian adults lands a median 0.1 points from the Census's own figure; 95% of counties within 2.3, the worst 4.9.

What drawing a population adds

A population is a sample of these weighted people, so small counties vary from draw to draw. Largest gap per county between the people drawn and the county's records, counties with at least 30 people.

Trait10,000 people100,000 people
Median95% of counties withinMedian95% of counties within
Race and ethnicity0.42.00.11.5
Education2.37.90.85.9
Household income1.25.40.32.7

Party lean and 2024 turnout (modelled)

No Census record says how anyone votes, so these two traits are modelled. Each person starts from what Cooperative Election Study 2024 respondents like them (race, age, education and sex, in the Census West) said and did, with turnout checked against the voter file. Each county is then calibrated so its people's turnout and Democratic-minus-Republican margin match its 2024 presidential result (MIT Election Lab). Those results count votes for president, so turnout runs a point or so under ballots cast.

CheckMarginTurnout
Each county against its 2024 result (calibrated)median 0.0, worst 0.0median 0.0, worst 0.0
Demographics alone, given only the statewide resultmedian 22.2, worst 53.9median 2.4, worst 25.6
The same, with priors that never saw anyone from Californiamedian 23.2, worst 56.4median 2.8, worst 24.8

Leans against California's own survey respondents

Nothing was fitted to these: the share of each lean among California's adults, as modelled and as the CES's California respondents gave it.

DemocraticRepublicanNeitherTurnout
Model48%30%22%
CES California (n=4,858)51%29%20%
Priors that never saw anyone from California, applied to its 4,765 citizen respondents44%36%20%57%
CES California, citizens (n=4,765)51%29%20%53%

The county totals are right by construction: that is what calibration does. The honest test is the people alone, in the table above: given only the statewide result, how far each county's people land from its margin. Counties that vote very differently from people like them elsewhere in the region land furthest; the map shows where.

Within a county, calibration moves everyone's lean by the same factor, so lean by race inside one county is the weakest part. In the smallest counties the Census's five-year estimates carry wide margins, and where more presidential votes were cast than the estimate of citizens, turnout is held at 98%.

Use these traits to include or compare groups. They are not anyone's stated party, and results are never polls of real people.

Every county (58)
CountyAreaAdultsCensus gapVeterans (Census / people)Turnout 2024Margin: result / demographics alone
AlamedaSan Francisco-Oakland-Fremont1,323,1970.53% / 3%62%+54 / +25
AlpineSmall towns and rural California1,2950.33% / 8%58%+32 / +6
AmadorSmall towns and rural California35,0390.310% / 9%66%−28 / +1
ButteChico165,4770.37% / 7%60%−3 / +10
CalaverasSmall towns and rural California38,4150.39% / 9%72%−28 / −1
ColusaSmall towns and rural California16,0700.54% / 5%55%−28 / +13
Contra CostaSan Francisco-Oakland-Fremont909,0120.24% / 4%67%+38 / +20
Del NorteSmall towns and rural California21,4500.48% / 8%51%−16 / +3
El DoradoSacramento-Roseville-Folsom155,0290.37% / 8%75%−12 / +7
FresnoFresno734,2060.34% / 4%51%−4 / +20
GlennSmall towns and rural California20,8720.35% / 5%59%−35 / +5
HumboldtSmall towns and rural California109,2400.26% / 6%61%+28 / +7
ImperialEl Centro129,1480.23% / 4%52%−1 / +27
InyoSmall towns and rural California14,9580.28% / 9%63%−3 / +4
KernBakersfield-Delano653,5850.45% / 5%51%−21 / +18
KingsHanford-Corcoran112,1720.57% / 7%44%−23 / +19
LakeSmall towns and rural California53,2180.18% / 7%54%−1 / +1
LassenSmall towns and rural California24,7450.27% / 7%49%−54 / +2
Los AngelesLos Angeles-Long Beach-Anaheim7,789,5270.23% / 3%58%+33 / +25
MaderaFresno117,2680.45% / 4%56%−21 / +15
MarinSan Francisco-Oakland-Fremont207,9830.24% / 4%78%+64 / +15
MariposaSmall towns and rural California14,1410.28% / 9%71%−21 / +2
MendocinoSmall towns and rural California71,3470.36% / 7%60%+27 / +4
MercedMerced206,8710.34% / 4%52%−4 / +19
ModocSmall towns and rural California6,9610.412% / 10%61%−47 / −1
MonoSmall towns and rural California10,8190.45% / 7%63%+20 / +8
MontereySalinas325,3390.34% / 4%61%+30 / +20
NapaNapa108,6430.35% / 5%68%+35 / +14
NevadaSmall towns and rural California85,0700.48% / 8%76%+12 / +5
OrangeLos Angeles-Long Beach-Anaheim2,500,6870.33% / 3%65%+3 / +19
PlacerSacramento-Roseville-Folsom327,8690.47% / 7%75%−9 / +11
PlumasSmall towns and rural California16,0870.510% / 11%64%−17 / −1
RiversideRiverside-San Bernardino-Ontario1,881,2310.46% / 6%57%−1 / +19
SacramentoSacramento-Roseville-Folsom1,229,4810.55% / 6%59%+20 / +18
San BenitoSan Jose-Sunnyvale-Santa Clara50,2740.34% / 4%64%+13 / +20
San BernardinoRiverside-San Bernardino-Ontario1,636,7260.35% / 5%53%−2 / +22
San DiegoSan Diego-Chula Vista-Carlsbad2,601,4570.27% / 7%64%+17 / +20
San FranciscoSan Francisco-Oakland-Fremont716,7270.33% / 2%65%+65 / +25
San JoaquinStockton-Lodi588,5100.34% / 4%53%−1 / +18
San Luis ObispoSan Luis Obispo-Paso Robles232,3110.26% / 6%69%+11 / +13
San MateoSan Francisco-Oakland-Fremont597,2450.43% / 3%67%+50 / +21
Santa BarbaraSanta Maria-Santa Barbara344,3020.25% / 5%64%+27 / +19
Santa ClaraSan Jose-Sunnyvale-Santa Clara1,511,9710.23% / 3%64%+40 / +23
Santa CruzSanta Cruz-Watsonville216,2130.34% / 4%70%+54 / +17
ShastaRedding142,2880.38% / 8%64%−36 / +3
SierraSmall towns and rural California2,3490.46% / 9%78%−24 / −1
SiskiyouSmall towns and rural California34,7760.49% / 10%63%−19 / +0
SolanoVallejo353,0880.48% / 8%60%+23 / +20
SonomaSanta Rosa-Petaluma392,6430.35% / 5%71%+46 / +11
StanislausModesto406,6110.34% / 4%56%−11 / +14
SutterYuba City73,9830.16% / 7%61%−31 / +10
TehamaSmall towns and rural California49,4710.47% / 7%58%−42 / +2
TrinitySmall towns and rural California13,1330.39% / 9%44%−9 / −5
TulareVisalia336,2720.34% / 4%51%−21 / +19
TuolumneSmall towns and rural California45,1930.310% / 9%65%−22 / +3
VenturaOxnard-Thousand Oaks-Ventura654,7620.25% / 5%68%+15 / +16
YoloSacramento-Roseville-Folsom176,2810.14% / 4%60%+36 / +23
YubaYuba City61,5430.38% / 8%52%−26 / +10

Sources

Records
ACS PUMS 2020–2024 5-year, California, adults 18+
Tables
ACS 2020–2024 5-year tables B01001, B01001B/D/H/I, B15001, B19001, B23025, B25008, B26001; out of sample: B21001
Geography
2020 Census tract to 2020 PUMA relationship file; tract population B01003; metro areas, OMB delineation of July 2023
Citizenship
ACS 2020–2024 5-year table B05003 (raked)
Party lean
Modelled. Priors: Cooperative Election Study 2024 common content (Harvard Dataverse doi:10.7910/DVN/X11EP6, CC0), citizen respondents in the Census West, validated 2024 vote and 7-point party ID with leaners as partisans. Calibration: 2024 county presidential returns, MIT Election Data and Science Lab (Harvard Dataverse doi:10.7910/DVN/VOQCHQ, CC0), presidential votes standing in for ballots cast.