Tens of millions of people across the US are again facing smoky skies and poor air quality as wildfire smoke from Canada drifts over the midwest, mid-Atlantic and north-east. About 109 million people were expected to experience another day of unhealthy conditions on Friday, with air pollution linked to fires in Ontario spreading south and east, according to air-quality updates from US government sources. Hazardous air over the Great Lakes and north-eastCities including Chicago and Detroit were blanketed by smoke, and residents were told to limit time outdoors after the US Air Quality Index (AQI) reached “hazardous” levels of 361 on Friday, the AirNow website said. Smoke moved into the Baltimore and Washington DC area overnight. By 6am eastern time, AQI readings were listed at 281 in Baltimore and 247 in Washington DC, which correspond to “very unhealthy” and “very unhealthy” categories respectively. In New York City, where smoke has been present since Tuesday, air quality was recorded at 184 early on Friday, classified as “unhealthy”. It later improved to 124, which falls under “Unhealthy for Sensitive Groups”. Philadelphia and Cleveland recorded readings of about 260, described by officials as “very unhealthy”. Other parts of Michigan, Minnesota and Wisconsin also reported AQI values in the “hazardous” range. Guidance for residents and expected changesMichigan officials advised residents to reduce indoor exposure by keeping windows closed, limiting door openings and using heating, ventilation and air conditioning systems rated Merv-13 or higher. They also recommended that anyone who must be outside for short periods wear an N95 or P100 respirator marked with NIOSH, according to a state alert. Some parts of the north-east and New England are expected to see improvement later on Friday as stronger winds from Quebec, outside the main wildfire area in north-western Ontario, push smoke away. Mark Parrington, a senior scientist at the Copernicus Atmosphere Monitoring Service, said wildfire activity in Canada has intensified in recent weeks. He added that forecasts show smoke continuing to move east across the North Atlantic and could reach Europe, underlining the scale of cross-border pollution. Organisers of the World Cup final in East Rutherford, New Jersey, are monitoring smoke patterns, with officials and sources telling ABC News that smoke currently over the mid-Atlantic could move back towards the north-east. However, a storm system approaching from the west bringing severe thunderstorms could worsen conditions by drawing smoke from higher levels down to the ground via rain. Air quality is expected to improve after the system passes late on Saturday, with authorities aiming for conditions suitable for a 3pm Sunday kick-off, while also monitoring whether smoke plumes could affect the match. Parrington said another smoky air mass could follow after the rain, and that increased fire intensity through Saturday could add more smoke to the atmosphere. Wildfires Spread Across Western USCanada’s largest wildfire near Wabakimi provincial park in Ontario has spread across 787,802 acres (318,812 hectares), the Canadian Interagency Forest Fire Center said. It is one of 194 out-of-control and large fires burning as of Thursday. Parrington said smoke plumes from wildfires in Canada’s north-west territories have reached the Arctic Ocean as well as other parts of the country. Nearly 6m acres are estimated to have burned, less than a quarter of the area consumed during Canada’s wildfire smoke episode in the US in 2023. In northern Minnesota, fires have burned more than 63,000 acres. In the west of the US, wildfires have also been reported in Oregon, Washington and Idaho. Forecaster Colin McCarthy said tens of thousands of lightning strikes across the Pacific Northwest have ignited dozens of new fires across Oregon and Washington. A 2025 study by Carnegie Mellon University’s Tepper School of Business estimated that wildfire smoke and prescribed burns caused $200bn in health damages in 2017 and were associated with 20,000 premature deaths. Co-author Nicholas Muller said research has linked fire smoke to higher morbidity and mortality risks, similar to other air pollutants. At the other end of the country, heavy rainfall in south and central Texas, including Texas Hill Country, exceeded 20in (50cm) in some places since Monday. The Guadalupe River near Comfort in Kerr county crested at 37ft above flood stage, AccuWeather said. AccuWeather’s Global Weather Center put a preliminary estimate of damage and economic losses at between $11bn and $13bn. It said the extreme rainfall aligns with findings from its climate research unit that rainfall totals above 4in in 24 hours have increased by 70% since 1995. Jonathan Porter, AccuWeather’s chief meteorologist, said describing extreme rainfall as “1-in-1,000-year” depends on probabilities that change as the climate warms, meaning such events can occur more often than past statistics suggest. Join the discussion? 18 July 2026
View full article
