Millions of Americans face air quality alerts from Minnesota to New York as authorities urge people to stay indoors Sign up for the Breaking News US newsletter email Tell us: have…

Millions of Americans face air quality alerts from Minnesota to New York as authorities urge people to stay indoors Tell us: have you been affected by the spread of wildfire smoke in the US and Canada? 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. 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. 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.” 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”.