A haze visible in parts of the Sacramento Valley is from multiple wildfires burning in Northern California. A north wind is pushing the smoke to the valley, and a high-pressure system is locking it in with little wind.

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

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.