About the Air District

Marin County

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.

Latest News
  • Sep
    2 2

    September 22, 2023

    Air District extends Spare the Air Alert through Saturday

    The Air District is extending a Spare the Air Alert through Saturday, September 23, due to continued wildfire smoke impacts across the region.

  • Sep
    2 1

    September 21, 2023

    Air District extends Spare the Air Alert through Friday

    The Air District is extending a Spare the Air Alert through Friday, September 22, due to continued wildfire smoke impacts across the region.

  • Sep
    2 0

    September 20, 2023

    Air District issues Spare the Air Alert through Thursday

    The Air District is issuing a Spare the Air Alert due to wildfire smoke for Wednesday, September 20 through Thursday, September 21, which bans burning wood, manufactured fire logs or any other solid fuel, both indoors and outdoors.

  • Sep
    1 9

    September 19, 2023

    Air District issues air quality advisory through Wednesday

    The Air District is issuing an air quality advisory for wildfire smoke through Wednesday, September 20. Smoke from fires in Northern California and Oregon is expected to impact air quality throughout the Bay Area area, causing air quality to reach high-moderate on the U.S. EPA’s Air Quality Index. Smoky, hazy skies may be visible and the smell of smoke is possible. Pollutant levels are NOT expected to exceed the national 24-hour health standard and there is no Spare the Air Alert in effect.

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

Air Quality in Marin 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.

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

Spare the Air Status

Last Updated: 2/14/2019