Smoke from Canada's wildfires has filled U.S. skies with an unhealthy haze for weeks, becoming a hallmark of the 2023 summer. The smoke raises a number of questions, from why the fires have lasted so long to how smoke keeps ruining air quality for tens millions of people in the U.S.
For many people, the smoke is worse than any other time in recent memory. And there are concerns about whether this might simply be the new normal — if people in the central and eastern U.S. should simply get used to the idea that their summers will be marked by weeks of smoke rather than blue skies and clear sunshine.
