Is the air quality good in Los Angeles?
On January 21, 2026, at 12:00 PM PT, Los Angeles, California, is experiencing poor air quality, with an Air Quality Index (AQI) of 99, just short of being classified as "unhealthy for sensitive groups".
Air quality is dynamic and, like the weather, can change frequently. Los Angeles ranks 34th among the most polluted cities in the world on Wednesday afternoon. There has also been an air quality alert issued by the National Weather Service for nearby San Diego (1).
Click here for a real-time air quality map of Los Angeles.
Today's air quality is unusually poor, but it is important to keep in mind that the average PM2.5 concentration in 2024 for Los Angeles was 10 µg/m3. This corresponds to an AQI of 42, which falls into the “good” category and was 2 times the WHO annual guideline of 5 µg/m3.
Los Angeles, California tied in ranking as 34th most polluted major city on Dec 13, 2025, 1:30 AM PT. Source: IQAir.
When will air quality improve in Los Angeles?
Poor air quality in Los Angeles is forecasted to peak on Thursday evening, after which weather conditions may allow for better pollutant dispersal (2).
Air quality Map of Los Angeles, California on January 21, 2025. Source: IQAir.
What is causing poor air quality in Los Angeles?
The current poor air quality in Los Angeles stems from a mix of seasonal, geographic, and human activities.
Winter stagnation is trapping fine particulate matter close to the surface, worsening conditions (3). Wood burning accompanying cool temperatures and vehicle emissions are adding to the ground-level pollution mix. The city is located in a basin encircled by mountains, helping to keep pollutants from dispersing.
Finally, a temperature inversion is preventing vertical air circulation and locking pollutants near ground level.
A mandatory residential "no wood burning" ban was issued notice by the South Coast Air Quality Management District for Thursday, January 22 (4). The ban applies to Los Angeles, Orange, Riverside, and San Bernardino Counties excepting the High Desert and Coachella Valley.
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
- Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
