You can put an App on your phone called "AirNow." During the fires 2 summers ago, our air quality index was over 800 a couple times - it was dark as night outside. You don't want to breathe that smoke, its toxic. My entire vegetable garden died and everything else was starting to turn yellow. My refuge was my greenhouse - even with the vents open, the air was amazingly fresh. The power of plants in an enclosed space.
After a couple weeks of that, I was so excited to see the sun, I took a picture.