More Canadian wildfire smoke shrouds US midwest, mid-Atlantic and north-east

The Empire State Building and the New York City skyline, seen through a layer of wildfire smoke, as viewed from Hoboken, New Jersey, on 17 July 2026. Photograph: Eduardo Muñoz/Reuters View image in fullscreen The Empire State Building and the New York City skyline, seen through a layer of wildfire smoke, as viewed from Hoboken, New Jersey, on 17 July 2026. Photograph: Eduardo Muñoz/Reuters More Canadian wildfire smoke shrouds US midwest, mid-Atlantic and north-east 109 million people face another day of poor air quality as smoke from blazes in Ontario drifts over the US Sign up for the Breaking News US newsletter email Tens of millions of Americans face another day of smoky skies, irritated eyes and bad air quality, as Canadian wildfire smoke spread again over huge swathes of the US, affecting around 109 million people across the midwest, mid-Atlantic and north-east. The pungent wildfire blanketed cities such as Chicago and Detroit , where residents on Friday were warned to stay indoors and reduce activity levels after the air quality index reached a “hazardous” 361, according to the government website AirNow . The smoke drifted into Baltimore and Washington DC overnight, creating very unhealthy air quality with index values of 281 and 247, respectively, as of 6am eastern time. In New York City , where smoke that has blanketed the city since Tuesday, air quality stands at an “unhealthy” 184. Tell us: have you been affected by the spread of wildfire smoke in the US and Canada? Read more Philadelphia and Cleveland had readings considered “very unhealthy” at about 260. Other parts of Michigan, Minnesota and Wisconsin also recorded readings in the “hazardous” range. Overall, the global air quality index showed pollution in five major North American cities at higher levels than Kinshasa or Nairobi in Africa – the next cities on the list. Nasa’s Fire Information for Resource Management System , or Firms, shows pockets of Canadian wildfires reaching deep into the Northwest Territories. In Michigan , the state’s department of environment, Great Lakes and energy recommended closing windows, minimizing the opening of doors and using HVAC systems rated Merv-13 or higher. “If you must be outdoors for short periods of time, an N95 or P100 respirator marked with NIOSH is recommended,” that alert said. But some cities in the north-east and New England are expected to get relief from smoky skies on Friday as stronger winds from Quebec – not from the wildfire zone in western Ontario – blow the smoke out. “There has been a clear intensification in wildfire activity for Canada over the past few weeks. Smoke from major fires – particularly in Ontario – [is] already having severe air quality impacts across cities in the Great Lakes region and the north-eastern United States,” said Mark Parrington, senior scientist at the Copernicus Atmosphere Monitoring Service. “Our forecasts show the smoke continuing to move eastwards across the North Atlantic, and potentially towa