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.

Smoke from wildfires burning in the northern Sacramento Valley may bring hazy skies and unhealthy air to parts of the Bay Area through Friday, air district officials said.