Cost to Own
United StatesCaliforniaSonoma County FIPS 06097 Data vintage ACS 2023 5-Year Rates updated 2026-09-10
Before you budget for Sonoma County FEMA rates natural hazard risk here Relatively High, with landslide its highest-ranked hazard against other US counties. It shapes what insurers charge and what owners repair. See what threatens homes here

Total monthly cost of ownership

Cost to Own a Home in Sonoma County, California

A $779,000 home here costs

$5,524

per month, all in, with 20% down at today's 6.76% 30-year fixed rate. By the 28% rule that takes a household income of about $236,500 a year.

P&I 73%Tax 8%Insurance 2%Utilities 4%Upkeep 12%

A standard mortgage calculator would have told you $4,046. The real number is $1,477 higher every month, 37% more than the payment most buyers budget for.

County median: $779,000
Under 20% adds PMI
Freddie Mac PMMS
CA average household

Compare with Contra Costa County · Solano County · Marin County · any county

Where every dollar goes

Only the first line is a mortgage payment. Change any assumption above and every figure below recalculates.

Principal & interest30-year fixed, $623,200 borrowed $4,046
Property tax0.716% effective rate, Sonoma County assessor via Census ACS $465
Homeowners insuranceCalifornia averages $1,403/yr (NAIC), or 0.186% of home value $121
Electricity34.74¢/kWh, California residential average, EIA $175
Water, sewer & trashUS household average $68
Maintenance reserve1% of home value per year, the cost nobody budgets $649
Total monthly $5,524

How Sonoma County compares

Sonoma County ranks 1,924th of 3,133 US counties by effective property tax rate, meaning property taxes here are lower than in 1,209 counties and higher than in 1,923. Within California it ranks 24th of 58.

Sonoma County 0.716% 14% lower than national
California average 0.714%
National median0.837%
Highest in America, Menominee County, WI3.636%

Paying the full bill when you don't have to?

California runs property tax relief: homestead, senior, veteran and disability programs, and nearly all of it requires a filing homeowners never make. See what you can claim in California. Buying instead? The state's down payment help is the program lenders forget to mention.

The numbers behind this page

MeasureSonoma CountySource
Median home value$779,000ACS B25077
Median real estate taxes paid$5,580ACS B25103
Effective property tax rate0.716%Derived
Median gross rent$2,093ACS B25064
Occupied housing units190,498ACS B25003
Population485,642ACS B01003
Residential electricity price34.74¢/kWhEIA 5.6.A, June 2026
30-year fixed mortgage rate6.76%Freddie Mac PMMS

The risk behind the insurance bill

FEMA rates Sonoma County's overall natural hazard risk Relatively High among US counties. Expected annual losses to buildings, people and agriculture here run about $605 million a year, county-wide, across every building in it, not per household.

One thing to be clear about: the insurance figure above does not know about any of this. It applies your state's average premium rate to the county's median home value, because published premium data does not exist at county level. Two counties in the same state get the same rate here even when FEMA rates one of them Very High and the other Very Low. So in a high-risk county treat the insurance line as a floor, not an estimate, and get a real quote before you budget.

Landslide FEMA National Risk Index percentile 99.8 Relatively High
Earthquake FEMA National Risk Index percentile 99.5 Relatively High
Drought FEMA National Risk Index percentile 99.3 Relatively High

Ratings are FEMA's own, relative to all US counties. A high drought or heat rating also shows up in the climate figures for Sonoma County.

Talk to someone who works this market

Every figure on this page is a county average. What your specific house costs, or what it would sell for, comes down to the street, the age of the roof and the condition of the systems. We will connect you with one licensed local agent who works Sonoma County every week. Free, no obligation, and we never sell your details to a list.

I'm looking to buy in Sonoma County I already own here and may sell

The weather behind that power bill

Sonoma County runs an average high of 84.1°F in its hottest month and a low of 36.9°F in its coldest, with 33.78" of precipitation a year and 60% of it falling in a single three-month stretch. That climate is what sets the $175 electricity line above: 410 cooling degree days and 2,904 heating degree days a year.

See the full Sonoma County climate breakdown , month by month temperatures, when the rainy season lands, snowfall, and what the heating and cooling actually cost.

Cities and towns in Sonoma County

Each has its own median home value and its own effective tax rate, which can differ noticeably from the county average of 0.716%.

Neighbouring counties

Counties sharing a border with Sonoma County. Crossing a state line can change the tax rate dramatically for an otherwise identical house.

All 58 counties in California

Questions about owning here

What is the property tax rate in Sonoma County?

The effective property tax rate in Sonoma County, California is 0.716% of home value per year. On the county's median home value of $779,000, that works out to about $5,580 annually, or $465 per month.

How much does it cost to own a home in Sonoma County?

A $779,000 home in Sonoma County, California costs approximately $5,524 per month with 20% down at 6.76%. That breaks down as $4,046 principal and interest, $465 property tax, $121 insurance, $243 utilities and $649 set aside for maintenance.

Why is this higher than the payment my lender quoted?

Lender quotes usually show principal and interest only, and sometimes property tax and insurance. They almost never include electricity, water or a maintenance reserve. Here those add about $892 a month, which is why the real cost is 37% above the mortgage payment alone.

Is it cheaper to rent in Sonoma County?

Median gross rent in Sonoma County, California is $2,093 per month, compared with $5,524 a month to own the median home all in. Renting is cheaper month to month, though rent does not build equity and is not fixed for 30 years.

How much is the electric bill in Sonoma County?

California residential electricity averages 34.74¢ per kWh. At the CA average household usage of 503 kWh per month, that is about $175. Actual bills vary considerably with house size, insulation and climate.

What salary do you need to buy a home in Sonoma County?

Using the standard 28% rule, housing costs at no more than 28% of gross income, buying the median home in Sonoma County, California at today's rate takes a household income of roughly $236,500 a year. That covers the full $5,524 monthly cost, not just the mortgage payment.

One county over In Contra Costa County, the same $779,000 home pays about $896 a year more in property tax than it does here. See what else changes across the line

Sources & methodology

  • Median home value, real estate taxes paid, gross rent, occupied units and population, US Census Bureau, American Community Survey ACS 2023 5-Year, tables B25077, B25103, B25064, B25003, B01003.
  • Effective property tax rate, median real estate taxes paid divided by median home value.
  • Mortgage rate, Freddie Mac PMMS, updated weekly.
  • Residential electricity price, US Energy Information Administration, Electric Power Monthly, Table 5.6.A.
  • Homeowners insurance, NAIC average premium for California ($1,403/yr), expressed as 0.186% of median home value and applied to the price above. A quote for your specific house will differ with roof age, claims history and coverage.
  • Maintenance (1%/yr) and water and sewer ($68/mo) are modelled national estimates, not quoted figures. Every assumption is editable above.

Full methodology