Air District Operations

The Air District is taking steps to ensure Bay Area air quality and public health are protected while the shelter-in-place orders are in effect. Permits for businesses adjusting operations to aid in the public health response will also be expedited. Read more... | en Español

Wood Burning Prohibited

Spare the Air Alert in effect through Friday, October 2.  Wood burning is banned.  Burn bans can occur year-round for wildfires. Smoke from wildfires is impacting air quality.  See our hourly air quality data for the most up-to-date information, as well as Press Releases@AirDistrict, and our Wildfire Safety Tips web page.  Sign up for Bay Area Air Alerts.  en Español

About the Air District

San Mateo County

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

Latest News
  • Sep
    28

    September 28, 2020

    Spare the Air Alert extended through Friday

    The Air District is extending the Spare the Air Alert due to wildfire smoke from the Glass Fire in Napa and Sonoma counties through Friday, October 2, which bans burning wood, manufactured fire logs or any other solid fuel, both indoors and outdoors. Wildfire smoke combined with high inland temperatures and vehicle exhaust may also cause unhealthy smog, or ozone, accumulation in the Bay Area.

  • Sep
    27

    September 27, 2020

    Spare the Air Alert extended through Monday

    The Air District is extending the Spare the Air Alert for wildfire smoke from the Glass Fire in Napa County and for smog through Monday, September 28, which bans burning wood, manufactured fire logs or any other solid fuel, both indoors and outdoors.

  • Sep
    26

    September 26, 2020

    Air District issues Spare the Air Alert for Sunday

    The Air District is issuing a Spare the Air Alert for smog for Sunday, September 27.

San Mateo County lies in the middle of the San Francisco Peninsula, south of San Francisco County, and north of Santa Clara and Santa Cruz counties. It is bounded by the Pacific Ocean to the west and San Francisco Bay to the east. Two San Mateo County representatives sit on the Air District’s Board of Directors.

Climate

Cool, foggy weather is prevalent along the western coast of the peninsula, particularly during the summer. Summertime average daily temperatures are moderate along the west coast and warm in the county’s east side. In the winter, average daily temperatures across the county range from mild to moderate. Winds are mild, with the highest wind speeds focused along the western coast. Rainfall averages about 20 to 25 inches per year at lower elevations and up to 36 inches in the Santa Cruz Mountains.

San Mateo County's climate is also affected by regional Bay Area climate influences.

Interactive Air Monitoring Stations Map

Air Quality in San Mateo 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 San Mateo County, ozone almost never exceeds health standards, and PM2.5 exceeds the national standard only on about one day each year. San Mateo County frequently receives fresh marine air from the Pacific Ocean, which passes over the coastal hills. In winter, PM2.5 may be transported into San Mateo County from other parts of the Bay Area, adding to wood smoke, which may lead to elevated concentrations, but these are rarely high enough to exceed health standards.

Interactive Air Quality Forecast Map

Resource Team

San Mateo County's Spare the Air Resource Team promotes ways to reduce air pollution in the local community.

Spare the Air Status
No Wood Burning
Spare the Air Status
  • Tuesday,
    9/29

    Spare the Air Alert in Effect

  • Wednesday,
    9/30

    Spare the Air Alert in Effect

Last Updated: 2/14/2019