skip to: Content | Footer
Contra Costa County
San Francisco County
San Mateo County
Santa Clara County
Community Air Risk Evaluation (CARE) Program
Community Grants Program
Public Participation Plan
Youth Outreach Education
Learn about Marin County - its climate, potential air pollution concerns, and current air quality. You can also view upcoming Air District events in Marin County and read about local efforts to improve air quality.
Marin County lies south of Sonoma County, bounded by the Pacific Ocean to the west, San Pablo Bay to the east, and the Golden Gate to the south. One Marin County representative sits on the Air District’s Board of Directors.
The west coast and southern portions of Marin County are often subject to cool marine air and substantial fog. Temperatures in these areas remain steady through the year because of the nearby ocean. The eastern side of Marin County is warmer and has less fog, due in large part to its distance from the ocean. The extra distance from the ocean allows the marine air to be heated before arriving at eastern Marin cities. Prevailing winds throughout the county are generally from the northwest, with wind speeds highest along the west coast. Annual rainfall in the mountains is generally higher than in most parts of the Bay Area, averaging 37 to 49 inches. The majority of rainfall across the county occurs November through March.
Marin County’s climate is also affected by regional Bay Area climate influences.
Interactive Air Monitoring Stations Map
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.
Along the Marin County coast and in southern Marin County, clean air from the Pacific Ocean helps to keep air pollution at a minimum. Elsewhere in Marin, ozone only rarely becomes a concern, but the hilly terrain and colder winter temperatures can trap PM2.5 near the surface, resulting in air quality that exceeds health standards.
Interactive Air Quality Forecast Map
Marin County’s Spare the Air Resource Team promotes various ways to reduce air pollution in the local community.
No Spare the Air Alert in Effect
Air Quality Widgets
Last Updated: 4/25/2016