About the Air District

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
  • The Air District is lifting an air quality advisory for the Bay Area due to wildfire smoke that was originally scheduled to last through today, Monday, July 14. Over the weekend, smoke from the Butler and Green wildfires had been moving down the Sacramento Valley and impacting air quality in portions of the Bay Area. However, as of Monday morning, the Bay Area is experiencing strong onshore winds, and smoke has remained mostly outside of the region. Air quality has been in the Good Air Quality Index category. Moderate onshore winds are expected to continue into Tuesday, keeping the smoke outside of the Bay Area. As the week progresses, these onshore winds will turn southerly in northern California, and this also is expected to keep the smoke from moving towards our region.

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  • The Air District is extending an air quality advisory for the Bay Area due to wildfire smoke from fires in northern Sacramento Valley through Monday, July 14. Smoke from the Butler and Green wildfires is still moving down the Sacramento Valley and is expected to continue to impact air quality in portions of the Bay Area on Sunday and Monday. Areas that are expected to be most impacted will be parts of the North Bay and East Bay and higher elevation locations. 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 at times on Sunday and Monday

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  • The Air District is extending an air quality advisory for the Bay Area due to wildfire smoke from fires in northern Sacramento Valley through Saturday, July 12. Smoke from the Butler and Green wildfires is moving down the Sacramento Valley and is expected to continue to impact air quality in portions of the Bay Area on Saturday. 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 at times on Saturday

     
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  • The Air District is issuing an air quality advisory for the Bay Area due to wildfire smoke from fires in northern Sacramento Valley for today, Thursday, July 10, and Friday, July 11. Smoke from the Butler and Green wildfires has been moving down the Sacramento Valley and is expected to impact air quality in the eastern portion of the Bay Area down to Santa Clara Valley on Thursday and Friday. 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 at times on Thursday and Friday

     

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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

Last Updated: 4/21/2017