Should we cancel due to air quality and ongoing wildfires?
That far out I would not be that concerned about the current fires.
These fires will most likely be out (or very contained by then.)
There may be new fires so worth checking
I would ask again around September 5th or so to find out about other fires.
This is a HUGE sad year for major fires in California so things can change.
Today's air quality (bad) should not impact your September 19-22 trip.
I would monitor the situation though.