Port Costa, California.
Typical home $658,968 (+2.2% in a year). San Francisco-Oakland-Berkeley, CA metro.
to buy the typical home at today's mortgage rate — +$1,370 (+66%) since Jan 2020.
- 1 year
- Up $14,246 +2%
- $644,723$658,968 since Sep 2025
- 5 years
- Down $51,536 -7%
- $710,504$658,968 since Sep 2021
Monthly payment to buy the typical home
Home value × that month's 30-year mortgage rate, 20% down, principal and interest. This is the line households feel: prices and rates compound each other.
- Port Costa$3,459
- California$3,997
- United States$1,922
At the last five years' pace, prices here aren't rising.
Typical home values in Port Costa, CA rose 2.2% over the past year — faster than the nation's +1.2%.
Living in Port Costa, Contra Costa County, California
Port Costa, in Contra Costa County, had 190 people in the 2020 census. Unemployment in Contra Costa County was 5.0% in August 2026, and the county had 0.1% more jobs in 2025 than the year before. The most people in Contra Costa County work in schools and health care, then professional services.
Written by AI Claude Sonnet 5.5 wrote this on 24 October 2026 from the figures here, a list of nearby places and what it knows. It can be wrong or out of date.
What it’s like
The place. Port Costa is a very small community on the Carquinez Strait, with far fewer residents than most towns. Winters are cool and mild, with January highs and lows well above freezing, and summers turn hot by September. Rain and melted snow add up to a modest amount over the year.
Work. Most people here work in schools, hospitals and social care, in professional and business services, in shops, or in restaurants, hotels and entertainment. Across Contra Costa County, the largest workplaces include West Contra Costa Unified, Contra Costa Regional Medical Center and San Ramon Valley Unified. Household incomes across the county run high, and the number of jobs there has barely changed from the year before.
Things to do. For time outdoors, the Sacramento River and the San Joaquin River are both a longer drive away. Golden Gate Park, also a longer drive, is a large public garden, and the San Francisco Museum of Modern Art is a museum of modern and contemporary art, likewise a longer drive. Alcatraz Federal Penitentiary, the old island prison, is another museum visit reached from the city.
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What people in Contra Costa County work in
Employed residents by industry, from the Census survey. Contra Costa County had 374,448 jobs in 2025, 0.1% more than the year before (Bureau of Labor Statistics).
Weather through the year
Coldest in January, with highs near 57° and lows near 42°; warmest in September, with highs near 86° and lows near 56°. About 21 inches of rain and melted snow a year.
Average daily high and low, 1991–2020, at the Vallejo weather station, 4 miles away (NOAA).
Largest workplaces in Contra Costa County
- West Contra Costa UnifiedSchool district2,751FTE
- Contra Costa Regional Medical CenterGeneral hospital2,584FTE
- San Ramon Valley UnifiedSchool district2,519FTE
- 24 Hour Home CareSenior citizens centers2,496
- Mt. Diablo UnifiedSchool district2,466FTE
- John Muir Medical Center - WCGeneral hospital2,143FTE
- Antioch UnifiedSchool district1,552FTE
- JT Thorpe and SonRefractory fireproofing1,523
Staff on average in 2025, as each workplace reported it to OSHA with its injury records: 573 workplaces with 20 or more staff, 81,677 people in all across the county; Port Costa has none of its own. School districts come from the Common Core of Data (NCES, 2023–24) and hospitals from their Medicare cost reports (CMS, 2023); FTE marks full-time equivalent staff. Not listed: many offices and banks, which need not report to OSHA; military bases, whose staff OPM withholds; and, in about half the states, city and county governments.
Natural hazards
- EarthquakesRelatively high
- LandslidesRelatively moderate
- WildfireRelatively moderate
FEMA’s National Risk Index (December 2025) rates the risk each natural hazard poses to the people, buildings and farms in Port Costa’s census tracts, against the rest of the country; all of them together, relatively high. It is meant for planning, not a substitute for a local risk assessment or a flood map: FEMA’s index.
From the U.S. Census Bureau’s 2020 census and its American Community Survey (2020–2024 five-year estimates), and the Bureau of Labor Statistics. A survey, so each figure has a margin of error, and figures it is not sure of are left out. More on Contra Costa County and the San Francisco-Oakland-Berkeley, CA metro.
Port Costa home values
Zillow measures a city over its municipal boundary. Against the state and national figures, mid-tier homes, smoothed and seasonally adjusted.
- Port Costa$658,968
- California$761,538
- United States$366,157
When this market ran hot
Each cell is that month's year-on-year home-value growth. Read left to right, top row is the latest year — the 2021–22 band is the boom.
Zip codes with a Port Costa address
A different geography, not a breakdown. The figure above covers the municipality; these zips cover everywhere the Post Office calls Port Costa — often including townships beyond the city limits. Both come straight from Zillow, and they are not expected to average out.