California’s Progress, Challenges Noted in American Lung Association 26th Annual “State of the Air” Report

Released today, the American Lung Association’s 26th “State of the Air” report demonstrates California’s clean air policies and investments are working to cut harmful pollution. Despite facing the most difficult air pollution challenges in the United States, California’s leadership has continued to reduce ozone and particle pollution in the state. The “State of the Air” report release follows recent announcements that the federal government intends to roll back lifesaving clean air protections.

“In light of federal proposals to slash our clean air protections, local and state air agencies need – and must use – all available resources and tools to protect the health of all Californians, especially those most overburdened by pollution and climate impacts today,” said Mariela Ruacho, Senior Manager for Clean Air Advocacy with the American Lung Association. “Homegrown strategies like indirect source rules, vehicle smog checks and incentive programs, healthier land use, and transportation planning are more important than ever – and need our full support.”

The “State of the Air” report presents county-level data on unhealthy ozone pollution days, particle pollution days, and annual particle pollution levels and issue grades and ranks for counties and rankings for cities for each pollutant. The report finds that over 34.3 million Californians (88%) live in a community with at least one failing grade, and 22.9 million (59%) live in a community with three failing grades.

“The air pollutants covered in this report are widespread and can impact anyone’s health. Both ozone and particle pollution can cause premature death and other serious health effects such as asthma attacks, heart attacks and strokes, preterm births, and impaired cognitive functioning later in life. Particle pollution can also cause lung cancer,” said Ruacho. “Unhealthy air is inequitable and unaffordable. To protect against these costly health emergencies, California must double-down on investments to reduce wildfire risk, spur zero-emission transportation and energy sources, and align transportation funding with pollution reduction needs.”

Notable California findings from the “State of the Air” 2025 report:

California communities ranked among Most Polluted Cities:

Nine California cities appear among the Top 25 Most Polluted Cities lists in “State of the Air” 2025, including six that appear on the list for all three pollutants: Bakersfield, Fresno-Hanford-Corcoran, Los Angeles-Long Beach, Sacramento-Roseville, San Jose-San Francisco-Oakland, and Visalia. El Centro and Redding-Red Bluff each appear the list for most ozone days and one of the two particle categories; the San Diego-Chula Vista-Carlsbad metro area appears among the most polluted for ozone.

Cleanest ever reports for many California cities:

Despite many cities appearing on most-polluted lists, 12 California metropolitan areas had their best reports ever in the history of the “State of the Air” series in 2025, including Fresno that posted the cleanest report for all three pollution categories. Other cities achieving their best-ever report for at least one pollutant include: Bakersfield, Chico, Los Angeles-Long Beach, Sacramento, Salinas, San Diego, San Luis Obispo, Santa Maria-Santa Barbara, Santa Rosa-Petaluma and Visalia. This reflects on the effectiveness and urgency of continuing California’s long history of local and state clean air policies and investments.

California communities appear among Cleanest Cities:

Salinas and Santa Rosa-Petaluma appear on two Cleanest Cities lists (zero unhealthy ozone days and low annual particles). San Luis Obispo and Santa Barbara each appear on the cleanest list for short-term particles with no unhealthy days reported. Only Salinas appeared on a Cleanest Cities list in the 2024 report as major wildfires had significant impacts on clean air progress.

Southern California remains America’s most ozone-impacted region: Local, state and federal policies have helped Los Angeles-Long Beach cut unhealthy ozone days by nearly 40 percent since the first “State of the Air” 2000 report, but the metro area remains the most ozone-polluted (“smoggiest”) city in America. San Bernardino County experienced five months-worth (152 days) of ozone days in “State of the Air” 2025. Adoption and implementation of local rules to clean up smog-forming pollution generated by warehouse, rail yards and port operations and shifting to zero-emission appliances will be vital to maintaining momentum.

Particle progress and challenges in the San Joaquin Valley: The San Joaquin Valley has shown progress in reducing harmful air pollution but remains the most impacted region in the United States for both particle pollution categories. Bakersfield ranks as the most particle-polluted city in the nation, both for short-term and annual levels. Visalia and Fresno also appear among the Top 5 most polluted on both particle measures in “State of the Air” 2025. Phasing out agricultural burning, maintaining state investments in cleaning up heavy-duty trucks, and off-road agricultural equipment incentives are critical to ongoing local progress.

Nationally, the “State of the Air” report found that 156 million people in the U.S. (46%) live in an area that received a failing grade for at least one measure of air pollution and 42.5 million people live in areas with failing grades for all three measures. The report also found that a person of color in the U.S. is more than twice as likely as a white individual to live in a community with a failing grade on all three pollution measures. Notably, Hispanic individuals are nearly three times as likely as white individuals to live in a community with three failing grades. 

 In this year’s “State of the Air” report, the Lung Association is calling on everyone to support the EPA. EPA is essential to protecting people’s health from ozone and particle pollution. Without EPA staff and programs, families won’t know what’s in the air they are breathing, and efforts to clean up air pollution will be undone. Join the American Lung Association in advocating to protect EPA’s expert staff and lifesaving programs. See the full report results and take action at Lung.org/sota.