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About the Air District

Contra Costa County

About the Air District
  1. Air District
  2. About the Air District
  3. In Your Community
  4. Contra Costa County

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

Contra Costa County lies east of the San Pablo Bay, bounded by Alameda County to the south, San Joaquin County to the east, and Solano and Sacramento counties to the north. Four representatives sit on the Air District’s Board of Directors.

Latest News
  • Air District allocates $1.3 million to improve air quality in West Contra Costa County schools
    June 04, 2025

    The Air District's Board of Directors approved allocating $4 million in Community Air Protection Incentives funding to support home and school air filtration programs in Bay Area communities at their June 4 meeting. As part of this initiative, the Air District Board authorized up to $1.3 million of upgrades in public schools in Richmond, North Richmond, San Pablo, and Tara Hills. An additional $1.7 million will be used to expand air filtration upgrades in schools in Bayview-Hunters Point in San Francisco, and $1 million will be allocated to the Air District’s Home Air Filtration program.

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  • Air District extends air quality advisory for wildfire smoke through Thursday
    June 04, 2025

    The Air District is extending an air quality advisory due to wildfire smoke from Canadian wildfires in the Bay Area through Thursday, June 5. Smoke from various Canadian wildfires in Alberta, Saskatchewan, and Manitoba is expected to impact air quality in the Bay Area through Thursday. Conditions can change rapidly and the amount and location of smoke at ground level are hard to predict. The public can check for real-time smoke pollution levels in their local area with the U.S. EPA’s Fire and Smoke Map. Smoky, hazy skies may be visible, the smell of smoke is possible, and air quality may become unhealthy through Thursday, June 5.

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  • Air District extends air quality advisory for wildfire smoke through Wednesday
    June 03, 2025

    The Air District is extending an air quality advisory due to wildfire smoke from Canadian wildfires in the Bay Area through Wednesday, June 4. Smoke from various Canadian wildfires in Alberta, Saskatchewan and Manitoba is expected to impact air quality in the Bay Area through Wednesday. Conditions can change rapidly and the amount and location of smoke at ground level are hard to predict. The public can check for real-time smoke pollution levels in their local area with the U.S. EPA’s Fire and Smoke Map. Smoky, hazy skies may be visible, the smell of smoke is possible, and air quality may become unhealthy through Wednesday, June 4.

    Learn More
  • Air District issues air quality advisory for wildfire smoke for Monday and Tuesday
    June 02, 2025

    The Air District is issuing an air quality advisory due to wildfire smoke from Canadian wildfires in the Bay Area for Monday, June 2 and Tuesday, June 3. Smoke from various Canadian wildfires in Alberta, Saskatchewan, and Manitoba is expected to impact air quality in parts of the Bay Area on Monday and Tuesday. Conditions can change rapidly and the amount and location of smoke at ground level is hard to predict. The public can check for real-time smoke pollution levels in their local area with the U.S. EPA's Fire and Smoke Map. Smoky, hazy skies may be visible, the smell of smoke is possible and air quality may become unhealthy on Monday and Tuesday.

    Learn More
Other News Articles

Climate

Temperatures in and around the San Ramon and Diablo Valleys are warm in the summer and cool in the winter, largely because of their distance from the moderating effect of water bodies and because the California Coast Range blocks marine air flow into the valleys. The Carquinez Strait region remains temperate due to its proximity to water and oceanic air flows. In winter, average daily temperatures are mild, with tule fog common at night. Average summer temperatures are typically mild overnight and warm during the day, with cooler temperatures and stronger winds more common along the western coast. Wind speeds are generally low throughout the region and winds typically blow from northwest to southwest. However, strong afternoon gusts are common in the northern portion of the county around the Carquinez Strait. Annual rainfall averages between 18 and 23 inches across the county. 

Interactive Air Monitoring Stations Map

Air Quality in Contra Costa 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.

Ozone and PM2.5 infrequently exceed health standards in the portion of Contra Costa County west of the East Bay hills. The San Francisco Bay keeps air temperatures above freezing in winter and well below 100 degrees on even the warmest summer days. 

In eastern Contra Costa County, summer afternoon temperatures frequently approach triple digits, spurring ozone levels to exceed health standards. In winter, PM2.5 can be transported westward through the Carquinez Strait from the Central Valley where it adds to wood smoke, causing health standards to be exceeded.

Interactive Air Quality Forecast Map

Spare the Air Status

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Last Updated: 4/21/2017