When will hazardous air quality start to clear up from Canadian wildfires?

When will hazardous air quality start to clear up from Canadian wildfires?

 An unusually intense wildfire season in Canada has filled the skies of the Northeast with scenes of smoke and forced the issuance of air quality alerts for millions. The smoke-filled air is being pumped into the northern tier by a series of weather features. Without an immediate reduction in wildfire activity, communities across North America could be under the threat of smoke for an extended period.