SAN FRANCISCO (KRON) — The Bay Area Air Quality Management District is extending a Spare the Air Alert through Friday due to continued wildfire smoke impacts across the region.

“These wildfires continue to generate a large amount of smoke which is being transported into the Bay Area,” air district officials wrote.

After a very smoky Wednesday, air quality was still in the “unhealthy for sensitive groups” range on the U.S. EPA’s Air Quality Index throughout the Bay Area Thursday.

KRON4 Meteorologist John Shrable said current conditions are “comparatively better than yesterday.”

Shrable said, “Smoke and haze will continue today.”

The smoke plumes are being generated by wildfires burning near the California-Oregon border, including: Deep Fire, South Fork Complex, SRF Lightning Complex, Happy Camp Complex, and Smith River Complex.

Newly-generated smoke billowing from these wildfires will be blown north toward Oregon as wind directions shift on Friday, Shrable said. In the Bay Area, skies are still smoky due to “residual smoke that has settled in. Tomorrow, air quality should be improved,” he said.

(Graphic courtesy

Spare the Air Alerts are issued when ozone or particulate matter pollution is forecast to reach unhealthy levels. Plumes of wildfire smoke are laden with tiny toxic particles called PM2.5. wrote, “Air is almost always on the move, and pollution can easily drift from one reporting zone to another. This is particularly true in the Bay Area, which forms a single air basin, and where winds can blow pollution from one location into neighboring valleys.”

When air quality is unhealthy, it is important that Bay Area residents protect their health by avoiding exposure. “Smoke can irritate the eyes and airways. Elevated particulate matter in the air can trigger wheezing in those who suffer from asthma, emphysema or COPD,” air district officials wrote.