Air quality is unhealthier-than-average for some people Thursday as winds are blowing wildfire smoke across the Northern California region.

Smoke from the Green Fire and other wildfires burning in and near Shasta County are polluting the air over the North State. The Shasta County Air Quality Management District and Shasta County Health and Human Services Agency advised people — especially those with health issues — to stay indoors when air is smoky.

The Bay Area Air District issued an air quality advisory on Thursday due to smoke from fires in the Sacramento Valley, which is expected to drift into the region, reaching all the way to the Santa Clara Valley.