SAN DIEGO (FOX 5/KUSI) — The American Lung Association’s 2026 list of most polluted places to live has ranked San Diego’s air quality among the worst in the country.
The American Lung Association‘s 27th annual “State of the Air” report found nearly half of U.S. children are breathing unhealthy levels of pollution in the air. The report grades counties based on how much smog (ground-level ozone air pollution) and soot (particle pollution) levels are in the air over a three year period, and San Diegans are among 75.9 million people, including 33.5 million children, living across the country with a failing grade.
Air advisory in southern San Diego due to hydrogen sulfide
San Diego ranked 59th last year, and was listed as the 5th most polluted place to live in 2026 for year-round particle pollution, which the report stated was the biggest change on the entire list.
With a population of 3.2 million, the San Diego-Chula Vista-Carlsbad metropolitan area in 5th place falls below Fresno-Hanford-Corcoran, CA at number four; Eugene-Springfield, OR at number three; Brownsville-Harlingen-Raymondville, TX at number two; and the most polluted area on the list — Bakersfield-Delano, CA.
Visalia, CA and Los Angeles-Long Beach, CA metropolitan areas fall just after San Diego on the list at numbers six and seven.
The San Diego metropolitan area also ranked as the 7th most ozone-polluted city in the U.S. for 2026.
San Diego got a big F grade on its annual report card for partial pollution, an F in ozone levels and a D in short-term 24-hour particle pollution. View the report card for your state and county here.
Locally, the San Diego County Air Pollution Control District (SDAPCD) monitors air quality and has been actively monitoring hydrogen sulfide levels in southern San Diego from transboundary wastewater and sewage flows near the Tijuana River Valley, which have been spiking up and down in recent months.
View real-time air quality in your area at airnow.gov.
The American Lung Association says fine particulate matter air pollution, also known as PM2.5, particle pollution or soot, can be deadly and comes from wildfires, wood-burning stoves, coal-fired power plants, diesel engines and other sources.
The report also found that over 129 million people (38% of the nation’s population) lived in counties earning F grades for ozone pollution, which is nearly 4 million more than last year’s report, and is worsened by things like extreme heat and smoke.
State-of-the-Air-2026-ReportDownload
The report found only one city — Bangor, Maine — made the cleanest cities list in 2026 for all three pollution measures.
Compare that to last year when two cities made the list, and in 2024 when five cities made the cleanest cities list, reflecting an overall worsening of air quality across the country, according to the report.
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