Heat Dome Drives Smoke From Canadian Wildfires Across Northeast United States
A high-pressure heat dome is trapping wildfire smoke from Canada and intensifying heat, leading to hazy conditions and air-quality alerts across the Northeast.
Wildfire smoke from Canada and the Great Lakes drifted into the Northeast on Tuesday, turning the sky over Manhattan hazy and prompting air-quality alerts in several jurisdictions. The haze is expected to persist into Wednesday and could worsen as a persistent high-pressure system, known as a heat dome, keeps the smoke near the surface.
New York City officials warned that air quality could deteriorate throughout Wednesday, though they noted that forecasts remain below the extreme levels recorded in 2023 when Canadian smoke pushed the city’s air-quality index to hazardous values. Officials advised individuals with respiratory or cardiovascular conditions to limit outdoor exposure.
The heat dome, visible on satellite imagery as a clear-sky region over the central United States, creates hot, humid conditions that combine with the smoke to make outdoor activity uncomfortable. Weather agencies have issued heat warnings for tens of millions of people from the Dakotas to New England, with temperatures projected to reach the upper 90s to over 100 °F in many areas on Wednesday.
The National Weather Service indicated that nearly 100 million people could be under "major" or "extreme" heat warning categories, while Environment Canada placed southern Ontario under an orange alert, the second-most severe level in its three-tier system.