Sonoma County is a large, urban-rural county encompassing 1,575 square miles. The county’s total population is currently estimated at 487,011. According to projections from the California Department of Finance, county population is projected to grow by 8.3% to 546,204 in 2020. This rate of growth is less than that projected for California as a whole (10.1%).
Geographic Distribution of Population
Sonoma County residents inhabit nine cities and a large unincorporated area, including many geographically isolated communities. The majority of the county’s population resides within its cities, the largest of which are clustered along the Highway 101 corridor. Santa Rosa is the largest city with a population of 168,841 and is the service hub for the entire county and the location of the county’s three major hospitals.
Since 2006, the county population has grown at an overall rate of 1.8% with the cities of Sonoma, Santa Rosa and Windsor experiencing the fastest growth rates.
Sonoma County population by city, 2006 and 2012
Source: E-5 Population and Housing Estimates for Cities, Counties, and the State (2011- 2012).
Sonoma County’s unincorporated areas are home to 146,739 residents, 30.1% of the total population. A significant number of these individuals live in locations that are very rural and geographically remote. Residents of these areas may experience social isolation and significant barriers in accessing basic services and supports such as transportation, health care, nutritious food and opportunities to socialize. Low-income and senior populations living in remote areas may face special challenges in maintaining health and quality of life. Of the county’s total senior population, age 60 and older, 12,144 (12%) are considered “geographically isolated” as defined by the Older Americans Act. (Source: California Dept. of Aging, California Aging Population Demographic Projections for Intrastate Funding Formula (2011).