About the Air District

Solano County

Learn about Solano County - its climate, potential air pollution concerns, and current air quality. You can also view upcoming Air District events in Solano County and read about local efforts to improve air quality.

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Solano County is bordered by Napa and Yolo counties to the north, Sacramento County to the east, and San Pablo Bay to the south. The Air District only has jurisdiction over the southwestern portion of the county, which includes Vallejo and Fairfield. One Solano County representative sits on the Air District’s Board of Directors.


During summer and fall months, high pressure offshore, coupled with thermal low pressure in the Central Valley, draws marine air eastward through the Carquinez Strait almost daily. Temperatures along the coast and inland tend to remain moderate. Winter temperatures range from cool overnight to moderate during the day, while summer temperatures range from moderate overnight to warm during the day. Afternoon westerly winds are common in the southern portion of the county, along the Carquinez Strait. Annual rainfall totals range from 13 inches near the coast to 22 inches inland in Fairfield. 

Interactive Air Monitoring Stations Map

Air Quality in Solano County

Ozone and fine particle pollution, or PM2.5, are the major regional air pollutants of concern in the San Francisco Bay Area. Ozone is primarily a problem in the summer, and fine particle pollution in the winter.

In summer, most of Solano County is exposed to prevailing westerly winds through the Carquinez Strait, which mixes and reduces ozone levels by drawing cooler, marine air from the Pacific Ocean and San Pablo Bay eastward. However, when the marine flow is weak or nonexistent, ozone levels may exceed health standards on a few days each year, mainly east of Suisun City.

In Solano County, PM2.5 concentrations can become elevated enough to exceed health standards during the winter when air pollution is transported from the Central Valley due to prevailing easterly winds. Local residential wood burning can also cause elevated particulate levels on cold, calm evenings during winter.

Interactive Air Quality Forecast Map

Spare the Air Status

Last Updated: 4/21/2017