Alameda County

Air District urges residents to skip the sparklers this Fourth of July
July 02, 2025

The Air District urges residents to celebrate responsibly this Fourth of July by avoiding personal fireworks, which can elevate air pollution and increase wildfire danger. Fireworks release smoke and fine particulate matter pollution, contributing to temporary spikes in unhealthy air quality.

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Air District extends air quality advisory for wildfire smoke through Monday
June 23, 2025

The Air District is extending an air quality advisory due to wildfire smoke from Canada and Alaska in the Bay Area through Monday, June 23. Smoke from various wildfires in western Canada and in Alaska is expected to continue to impact air quality in the Bay Area on Monday. 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.

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Air District issues air quality advisory for wildfire smoke for Sunday
June 22, 2025

The Air District is issuing an air quality advisory due to wildfire smoke from Canada and Alaska in the Bay Area for Sunday, June 22. Smoke from various wildfires in western Canada and in Alaska is expected to impact air quality in parts of the Bay Area on Sunday. 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 Sunday.

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Air District issues air quality advisory for smoke from Somersville brush fire for Wednesday evening
June 18, 2025

The Air District is issuing an air quality advisory due to smoke from the Somersville brush fire in Antioch. Smoke from this brush fire is expected to impact air quality in eastern Contra Costa County on Wednesday evening. 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. The Air District will continue to monitor conditions to see if impacts will continue on Thursday. Smoky, hazy skies may be visible, the smell of smoke is possible and air quality may become unhealthy as of Wednesday evening.

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June 12, 2025

Air District increases Vehicle Buy Back Program incentive and expands eligibility effective July 1
June 10, 2025

Air District and Chevron reach settlement with enhanced requirements for air monitoring and transparency
June 04, 2025

Air District allocates $1.3 million to improve air quality in West Contra Costa County schools

Climate

Along the county’s western coast, temperatures are moderated by the bay, which can act as a heat source during cold weather, or cool the air by evaporation during warm weather. It is generally sunnier farther from the coast, although partly cloudy skies are common throughout the summer. Average summer temperatures are mild overnight and moderate during the day. Winter temperatures are cool overnight and mild during the day. Highest temperatures are more common inland. Wind speeds vary throughout the county, with the strongest gusts along the western coast, often aided by dominant westerly winds and a bay-breeze effect. Rainfall totals average about 14 to 23 inches per year, with the highest totals in the northern end of the county and atop the Oakland-Berkeley hills.

Air Quality in Alameda 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 Alameda County west of the East Bay hills, ozone rarely exceeds health standards because the area is adjacent to San Francisco Bay, which tends to keep temperatures well below prime levels for ozone formation. PM2.5 is a more significant issue in this region due to cool winter nights with light winds, wood smoke, and occasional pollution transport from the Livermore Valley to the east.

Eastern Alameda County has the highest ozone levels in the Bay Area, with summer afternoon temperatures frequently approaching triple digits, spurring ozone levels to exceed health standards. In winter, PM2.5 can be transported westward through the Altamont Pass from the Central Valley where it adds to wood smoke levels, causing health standards to be exceeded.

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About the Air District

Alameda County

About the Air District

Climate

Air Quality in Alameda County

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