Tuesday night is when the high pressure system shifts to the east, the NWS says. This should allow south winds to return, which should usher out the smoke. But then it will bring on more heat and humidity. So get ready to turn your AC back on.

Air quality alerts are in effect on Tuesday in 10 states as toxic smoke from hundreds of wildfires burning in Canada continues to waft into the United States, creating hazy, gray skies over major metropolitan areas, including New York City.