Valid: Thursday, September 23 through Friday, September 24, 2021
This advisory is in effect through Friday afternoon. South Coast AQMD will issue an update if additional information becomes available.
Wildfires in central California are producing heavy smoke that is moving south towards the South Coast Air Basin. While the heaviest smoke will be present in the upper atmosphere across the region, impacts on surface air quality are expected in the San Bernardino, San Gabriel, and San Jacinto mountains.
As of Thursday at noon, Good and Moderate air quality index (AQI) levels are being measured throughout the region. However, elevated AQI levels are expected in mountain areas starting Thursday afternoon and continuing until Friday afternoon.
To help keep indoor air clean during periods of poor air quality, close all windows and doors and run your air conditioner and/or an air purifier. If possible, do not use whole house fans or swamp coolers that bring in outside air. Avoid burning wood in your fireplace or firepit and minimize sources of indoor air pollution such as candles, incense, pan-frying, and grilling. Limit the use of gasoline powered lawn and garden equipment.
Breathing of fine particulate matter can lead to a wide variety of cardiovascular and respiratory health effects such as heart attacks, asthma aggravation, decreased lung function, coughing, or difficulty breathing and may lead to premature death in people with heart or lung disease. Check air quality levels and take appropriate action as needed.
In areas affected by wildfire smoke, the AQI may reach Unhealthy for Sensitive Groups levels or higher from Thursday afternoon until Friday afternoon.
Areas of direct impacts and poor air quality may include portions of:
South Coast AQMD is the air pollution control agency for major portions of Los Angeles, Orange, San Bernardino, and Riverside counties, including the Coachella Valley. For news, air quality alerts, event updates and more, please visit us at, download our award-winning app, or follow us on , and .