Wildfires & Smoke
Wildfires
Cal Fire Incidents has information on all known wildfires in California, and is a good place to check if you notice smoke. Information on fires can be updated a few times a day. You can also check their map layout for a more visual approach.
Depending on jursidction fires may also show up on Inciweb you can use either their map view or their Table of Incidents.
Wildland Fires & Smoke has a lot of useful information about both fires and air quality.
Gaia GPS has layers for satellite heat detection and current wildfires for free users on both their web and mobile apps. Caltopo has corresponding map overlays for free users as well: fire activity and GOES 17 live fire detection.
Smoke & Air Quality Levels
AirNow Interactive Air Map Quality gives you nice rounded (projected) shapes for different AQI levels as well as the official AirNow high quality sensors.
AirNow Fire & Smoke Map you can now get the high quality (but slower updating) AirNow sensors combined with Purple Air's lower quality but faster updating ones in a single map! Purple Air's Map still has more sensors than the combined version above.
Windy has wind & air quality predictions 3 days out. The further out they are, the less useful they are, and fires can create and alter their own patterns, but it's at least a good general idea of what to expect. You can get a longer view out on just wind patterns. If you open the detailed forecast bottom panel there's a floating button above it for webcams in vincinity which can be useful.
Weather.gov Experimental Smoke Forecast includes a 24 hour prediction of smoke coverage, though rather zoomed out.
NASA's Worldview and BlueSky Daily Runs are great visual tools to show how smoke spread recently.
Great Basin Unified Air Pollution Control District covers Inyo & Mono.
San Joaquin Valley Air Piollution Control District covers some of the southern Sierra and surrounding areas.
California Smoke Information is an outreach point that multiple CA agencies use.
Historical burn areas
Caltopo allows free / anonymous members to check historical burn layers with their fire history map layer.
If you're a premium member of Gaia you can use their historical wildfire layer to see where past fires have been.