The red dots are Stay Indoors for seniors. Those fires up in BC have been active since spring. That’s the area devastated by the mountain pine beetle, which has had a population explosion in the last decade thanks to warmer winters (due, in turn, to global warming). Data 8/2/2017 from https://haze.airfire.org/airtools/v1/pnw-smoke.html?lat=47.3&lng=-119.5&zoom=6
Thanks so much for the explanation re the fires and smoke.
My late husband and I were in China several times and the smog in Beijing was yellow and dense. We were also there just before the Olympics, when the coal ‘industry’ was moved to surrounding islands and out of the city. It was amazing that one could actually see a few feet ahead but as soon as the games were over, much of the yellow stuff returned with much of the coal I hope they are getting more ahead of it now