The NOAA Hazard Mapping System Fire and Smoke Product image above shows a heavy amount of smoke above Northern California.
The NOAA Aerosol Watch image above supports this claim as there is an increased concentration of AODs in the northern region of California.
The AirNow Map image above shows an increased AQI in Northern California. The AQI in this region reaches a Very Unhealthy Level (201-300). This increased AQi is most likely due to smoke in the area which has increased the P.M 2.5 reaching the ground.