What is the largest city in Sonoma County, CA?

Santa Rosa is the largest city or town in Sonoma County, with about 177,090 residents.

How many ZIP codes are in Sonoma County?

Sonoma County includes 39 ZIP Code Tabulation Areas, including 94515, 94922, 94923, 94928, 94931.

What is the population of Sonoma County, CA?

About 485,040 people live in Sonoma County, based on American Community Survey 5-year estimates.

What counties border Sonoma County?

Sonoma County borders Solano County, Marin County, Napa County, Mendocino County, Lake County.

Sonoma County, CA: Cities, ZIP Codes & Local Data

Population

485,040

Land area

1,575sq mi

People per sq mi

308

ZIP codes

39

Sonoma County at a glance

The median household income is $104,674, 6% above the California median of $99,122.
A typical owner-occupied home is valued at $815,500 (11% above California) and median rent is $2,158 a month.
Its largest cities are Santa Rosa (177,090), Petaluma (59,247) and Rohnert Park (44,575).

Local data for Sonoma County, CA

Counts from official public data

Housing and community stats

Sonoma County, CA, American Community Survey 2020-2024

Full profile

Median household income

$104,674

Poverty rate

8.9%

Median home value

$815,500

Prices +0.5% in a year

Median rent

$2,158/mo

Homeownership

62.6%

Bachelor's or higher

38.5%

Median age

42.9

Average commute

25.1 min

Largest reported origins and ancestries: Mexican Americans (117,693), German Americans (59,978), Irish Americans (59,215).

Home values and rents Income, education and commute

Economy and federal money

Jobs, income, federal spending and pandemic loans

Details

Unemployment rate

4.3%

Sep 2026, -0.3 pts in a year

Average annual pay

$73,248

206,393 jobs, 2025

Income per person

$88,832

BEA, 2024

Federal spending

$3.3B

FY 2026, $6,788 per person

PPP loans

$1.6B

16,934 loans, 161,898 jobs reported

Campaign donations

$10.3M

Itemized, 2026 cycle

Economy Federal spending PPP loans

How people get to work

Sonoma County, CA, workers 16 and older. American Community Survey 5-year estimates

Drove alone69.4%
Carpooled9.4%
Public transit1.1%
Walked2.5%
Bicycle0.7%
Taxi, ride-hailing, motorcycle or other1.1%
Worked from home15.9%

Average one-way commute: 25.1 minutes for people who do not work from home.

Environment and hazard risk

Sonoma County, CA, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively High

Top: landslide

Storm events since 1996

806

Most often flood

Flood insurance policies

1,790

1.1% of homes, county

July high / Jan low

84° / 38°F

33.8 inches of rain a year

Hazards, floods and storm history Check a flood zone 48 historic places

Health statistics

Share of adults in Sonoma County, CA, CDC PLACES estimates

All 40 measures

Obesity

26.1%

U.S. 33.3% -7.2 pts

Diabetes

10.7%

U.S. 12.1% -1.4 pts

Smoking

10.6%

U.S. 12.8% -2.2 pts

Uninsured (18-64)

8.4%

U.S. 11.1% -2.7 pts

Cities, towns and ZIP codes in Sonoma County

Population shown

Frequently asked questions

What is the largest city in Sonoma County, CA?: Santa Rosa is the largest city or town in Sonoma County, with about 177,090 residents.
How many ZIP codes are in Sonoma County?: Sonoma County includes 39 ZIP Code Tabulation Areas, including 94515, 94922, 94923, 94928, 94931.
What is the population of Sonoma County, CA?: About 485,040 people live in Sonoma County, based on American Community Survey 5-year estimates.
What counties border Sonoma County?: Sonoma County borders Solano County, Marin County, Napa County, Mendocino County, Lake County.