Solano County is a county located in the U.S. state of California. As of the 2020 census, its population was 453,491. The county seat is Fairfield. Solano County comprises the Vallejo–Fairfield metropolitan statistical area, which is also included in the San Jose–San Francisco–Oakland, combined statistical area. Solano County is the northeastern county in the nine-county San Francisco Bay Area region. A portion of the South Campus at the University of California, Davis, is in Solano County.

History

Solano County was one of the original counties of California, created in 1850 at the time of statehood. At the request of General Mariano Guadalupe Vallejo, the county was named for Chief Solano of the Suisun people, a Native American tribe of the region and Vallejo's close ally. Chief Solano at one time led the tribes between the Petaluma River and the Sacramento River. The chief was also called Sem-Yeto, which signifies "brave or fierce hand." The chief was given the Spanish name Francisco Solano during baptism at the Catholic Mission, and is named after the Spanish Franciscan missionary, Father Francisco Solano. "Solano" is a common surname in the north of Spain, especially in Navarra, Zaragoza, and La Rioja. Travis Air Force Base is located just east of Fairfield. Between 2017 and 2023, California Forever purchased over 50,000 acres of land in the county for an estimated $900 million to develop a new city.

Region

Solano County is the easternmost county of the North Bay. As such, it is sometimes reported by news agencies as being in the East Bay. Additionally, a portion of the county extends into the Sacramento Valley, geographically.

Geography

According to the U.S. Census Bureau, the county has a total area of 906 sqmi, of which 84 sqmi, comprising 9.3%, are covered by water. Solano County had several cinnabar mines that were worked in the first half of the twentieth century, including the Hastings Mine and St. John's Mine.

Adjacent counties

National protected area

Flora and fauna

Solano County has a number of rare and endangered species, including the Delta green ground beetle, the wildflower Lasthenia conjugens, commonly known as Contra Costa goldfields, and the annual plant Legenere limosa or false Venus' looking glass.

Transportation

Major highways

Public transportation

Solano County is served by several transit agencies: Each agency interconnects with the others, enabling transit trips throughout the county. Service also connects with BART stations in Contra Costa County. Transit links are provided to Napa, Yolo and Sacramento counties as well. Greyhound and Amtrak provide long-distance intercity service.

Airports

General aviation airports in Solano County that are open to the public are the Nut Tree Airport and Rio Vista Municipal Airport.

Demographics

2020 census

2014

A 2014 analysis by The Atlantic found Solano County to be the 5th most racially diverse county in the United States, behind Aleutians West Census Area and Aleutians East Borough in Alaska, Queens County in New York, and Alameda County in California.

2011

Places by population, race, and income

2010

The 2010 United States Census reported that Solano County had a population of 413,344. The racial makeup of Solano County was 210,751 (51.0%) White, 60,750 (14.7%) African American, 3,212 (0.8%) Native American, 60,473 (14.6%) Asian, 3,564 (0.9%) Pacific Islander, 43,236 (10.5%) from other races, and 31,358 (7.6%) from two or more races. Hispanic or Latino of any race were 99,356 persons (24.0%). At 52,641 Filipinos in the county making up 12% of the population, Solano County has the largest percentage Filipino population of any county in the United States.

2000

At the 2000 census there were 394,542 people, 130,403 households, and 97,411 families in the county. The population density was 476 PD/sqmi. There were 134,513 housing units at an average density of 162 /mi2. The racial makeup of the county was 56.4% White, 14.9% Black or African American, 0.8% Native American, 12.8% Asian, 0.8% Pacific Islander, 8.0% from other races, and 6.4% from two or more races. 17.64% of the population were Hispanic or Latino of any race. 8.5% were of German, 6.4% Irish and 6.0% English ancestry according to Census 2000. 75.7% spoke English, 12.1% Spanish and 6.6% Tagalog as their first language. Of the 130,403 households 39.9% had children under the age of 18 living with them, 55.7% were married couples living together, 13.8% had a female householder with no husband present, and 25.3% were non-families. 19.6% of households were one person and 6.5% were one person aged 65 or older. The average household size was 2.90 and the average family size was 3.33. The age distribution was 28.3% under the age of 18, 9.2% from 18 to 24, 31.3% from 25 to 44, 21.7% from 45 to 64, and 9.5% 65 or older. The median age was 34 years. For every 100 females there were 101.5 males. For every 100 females age 18 and over, there were 100.2 males. The median household income was $54,099 and the median family income was $60,597. Males had a median income of $41,787 versus $31,916 for females. The per capita income for the county was $21,731. About 6.1% of families and 8.3% of the population were below the poverty line, including 10.3% of those under age 18 and 6.3% of those age 65 or over.

Crime

The following table includes the number of incidents reported and the rate per 1,000 persons for each type of offense (2011).

Cities by population and crime rates

Government and politics

Government

The Government of Solano County is defined and authorized under the California Constitution and law as a general law county. The County government provides countywide services such as elections and voter registration, law enforcement, jails, vital records, property records, tax collection, public health, and social services. In addition the County serves as the local government for all unincorporated areas. The County government is composed of the elected five-member Board of Supervisors, several other elected offices including the Sheriff-Coroner, District Attorney, Assessor/Recorder, Auditor-Controller, and Treasurer/Tax Collector/County Clerk, and numerous county departments and entities under the supervision of the County Administrator. As of March 2023, the members of the Solano County Board of Supervisors were:

Politics

Voter registration statistics

Overview

Solano County has been a Democratic stronghold in presidential and congressional elections, with Californians Richard Nixon (in 1972) and Ronald Reagan (in 1980 and 1984) being the only Republicans to win the county since 1928. However, the northern area of Solano County including Vacaville and Dixon have begun shifting right as evidenced by the 2022 midterms, voters in Congressional District 4 favored the Republican candidate 50.3% to 49.7%. Solano County is split between California's 4th, 7th and 8th congressional districts, represented by, and respectively. In the California State Assembly, Solano County is split between, and. In the California State Senate, it is in. On November 4, 2008, Solano County voted 55.82% in favor of Proposition 8, which amended the California Constitution to ban same-sex marriages. It was the only Bay Area county to approve the initiative. In the 2008 presidential election that day, Barack Obama carried the county by a 28.5% margin over John McCain, a larger margin than statewide (24%). According to the California Secretary of State, as of February 10, 2019, Solano County has 236,028 registered voters. Of those, 106,452 (45.1%) are registered Democrats, 50,006 (21.2%) are registered Republicans, and 66,558 (28.2%) have declined to state a political party. Democrats hold voter-registration advantages in all incorporated cities and towns in Solano County. However, Republicans lead in registration in the unincorporated communities of the county (40%-35%), making Solano the only county in the Bay Area where Republicans out-number Democrats in unincorporated communities. The Democrats' largest registration advantage in Solano is in the city of Vallejo, wherein there are only 8,242 Republicans (14.6%) out of 56,313 total voters compared to 33,753 Democrats (59.9%) and 12,157 voters who have declined to state a political party (21.6%).

Communities

Cities

Census-designated places

Other unincorporated communities

Population ranking

The population ranking of the following table is based on the 2020 census of Solano County. † county seat

Miscellania

Explanatory notes