Air regulators issued advisories Wednesday for counties in Southern California because of several large wildfires and extended the warning to 10 p.m. Thursday.
The South Coast Air Quality Management District issued the alert for Los Angeles, Orange and parts of Ventura, Riverside and San Bernardino counties.
Residents were smelling smoke in the air from the Sandy Fire, which burned more than 2,100 acres in Simi Valley and was 30% contained, according to Cal Fire officials.
Two fires were burning in Riverside County, the Bain Fire in Jurupa Valley and the Verona Fire in Homeland.
The Santa Rosa Island Fire in Santa Barbara County, which started Friday, was also filling the air with smoke over parts of LA County.
“Widespread moderate smoke impacts are expected across the LA Basin, Catalina Island, Inland Empire, and Coachella Valley,” according to the SCAQMD. “The Sandy Fire is expected to directly impact areas from Simi Valley to (the) San Fernando Valley and out to Arcadia where (the) Air Quality Index may reach the unhealthy for sensitive groups category or higher at times.”
According to air regulators, the Bain and Verona fires are expected to directly affect portions of the Inland Empire where the Air Quality Index may at times reach the Unhealthy for Sensitive Groups category or higher.
Smoke from the Santa Rosa Island and Sandy fires that is already over the ocean was expected to come onshore overnight, and weak winds are forecast for the coming days, hindering the dispersion of smoke dispersion from the region.
Depending on fire activity, smoke conditions were expected to improve Friday in areas not adjacent to active fires, officials said.
The AQMD advised the following precautions:
- Limit exposure by remaining indoors with windows and doors closed or seeking alternate shelter.
- Avoid vigorous physical activity.
- Run air conditioning and/or an air purifier. If possible, do not use swamp coolers or whole house fans that bring in outside air.
- Avoid burning wood in fireplaces or firepits and minimize sources of indoor air pollution — candles, incense, pan-frying and grilling.
- If outdoor activity is a must, a properly fit N95 or P100 respirator may provide protection.
Updated May 21, 2026, 11:11 a.m.
