Ontario wildfires intensify, sending smoke into the United States

Ontario’s wildfires had grown to 735,000 hectares, or 1.8 million acres, as smoke again drifted into the United States and left a broad swath of North America under hazy skies. Doug Ford said the province was facing 180 active wildfires, and the smoke was degrading air quality across the Midwest, Northeast and Mid-Atlantic.

The fire growth, from 650,000 hectares over the weekend, showed how quickly a provincial emergency became a cross-border public health problem. In parts of the United States, the haze threatened visibility, outdoor work, travel and recreation, while people with asthma, heart disease or other respiratory conditions faced the highest risk from the smoke. Public-health agencies in affected areas have been urging people to limit time outside and rely on filtration when indoor air turns unsafe.

Ontario also moved to add more firefighting capacity. The province planned to buy 11 new aircraft to help respond to what Ford called a very difficult wildfire battle. The scale of the fires and the smoke plume underscored how dry conditions, heat and difficult firefighting terrain can let blazes persist longer and push smoke hundreds of miles south and east.

The crisis quickly took on political heat as well. Donald Trump blamed Canada for the wildfire smoke and suggested adding the cost of pollution from the fires to tariffs. Ford said criticism of Canada’s efforts to stop the spreading forest fires was “absolutely unacceptable.”

The episode has become familiar across recent summers, but its footprint has widened. Coverage around the smoke event described dangerous air quality for tens of millions of people across North America, with Toronto and other cities experiencing the effects alongside U.S. communities far from the Ontario fire lines. That has put pressure on emergency managers, transportation officials and health agencies on both sides of the border to monitor air conditions, warn residents and adjust plans as the smoke shifts.