United States Air Quality Alert Issued Due to Canadian Wildfires

Air Quality Alert Issued for 20 US States Amid Canadian Wildfires

Smoke from wildfires burning in south-central Canada and parts of Minnesota is spreading across the US, prompting air quality alerts in more than 20 states with millions of Americans expected to face unhealthy air conditions this week.

What's Happening?

The smoke from the more than 180 active wildfires in northern Ontario made Chicago's air quality the worst in the world on Thursday evening, followed by Detroit and Minneapolis, according to IQAir's global rankings. The smoke has spread across several US states, from Minnesota, where multiple wildfires are also burning, to New York state, blanketing the skies in haze and worsening air quality.

Why it Matters for the US

In New York City, where the sky was tinged with an orange haze and the air smelled acrid, local officials urged residents to limit their outdoor time and cautioned elderly people, pregnant women, and people with other risk factors, such as heart and lung disease, to remain inside. "Today is expected to be the worst day of this event," said Zohran Mamdani, New York City's mayor, at a gathering on Thursday. "At 'unhealthy' levels, everyone – not just people with asthma or heart conditions, not just older adults – everyone may feel health effects. So today, every New Yorker should take precautions."

What Comes Next?

The National Aeronautics and Space Administration (Nasa) said that winds carried smoke from the Ontario fires "primarily south-east over much of the southern part of the province, as well as parts of Quebec and the US midwest and north-east, tinting the sky shades of gray and yellow and the sun orange in many areas." As of Thursday, air quality alerts have been issued for parts of North Carolina, Minnesota, Vermont, Connecticut, New York, Massachusetts, Rhode Island, New Jersey, New Hampshire, Pennsylvania, Illinois, Indiana, Ohio, Delaware, West Virginia, Colorado, Virginia, Maryland, Washington DC, Michigan, and Wisconsin.

According to a map of air quality conditions provided by the US Environmental Protection Agency, air quality was at "unhealthy" levels on Thursday in parts of Pennsylvania, Delaware, New Jersey, New York, Ohio, and Michigan, with officials urging residents to "take precautions by reducing outdoor activity." On Thursday afternoon, the air quality was rated as "very unhealthy" in parts of Pennsylvania, New York, Ohio, Michigan, Illinois, Wisconsin, Minnesota, and Indiana, while in certain parts of Pennsylvania, Michigan, including near Detroit, as well as areas of Ohio, Illinois, Wisconsin, and Minnesota, the air quality was listed as "hazardous," with officials urging residents there to stay indoors. The National Weather Service in Detroit warned on Thursday that "smoke is expected to be most dense this afternoon and tonight with reduced visibilities." In New York, officials extended the city's heat emergency plan operations, including the opening of hundreds of cooling centers, as "high temperatures and heat indices continue and smoke from significant, still-spreading wildfires in western Ontario, Canada, moves into the region." Kathy Hochul, New York's governor, announced that more than 100,000 N95-style masks were being made available to counties in need, with additional masks being made available for commuters at Penn Station and Grand Central. New York officials also warned that this could become New York City's "most significant smoke event" since 2023, when smoke from Canadian wildfires pushed air quality to hazardous levels and blanketed the city in an orange haze.