The NOAA Hazard Mapping System Fire and Smoke Product image above shows a heavy concentration of smoke originating from the state of California.
The AirNow Map image above shows that there is a heavy concentration of Particulate Matter above Northern California. At its maximum concentration the Air Quality Index reaches a Very Unhealthy, (Purple, 201-300).
The NRL/Monterey Aerosol image above supports this as there is an increased level of smoke surface concentration. At its maximum concentration the smoke surface concentration reaches above 512 ug/m*3.
The Weather.gov image above shows that in this region of California is a Red Flag warning due to an increased level of heat and slow windspeed resulting in an increased chance of fire growth. INCIWEB reports that in this region is the Dixie Fire, McCash Fire, River Complex Fire, and others. Together these fires have burned over a million acres of land.