The US National Weather Service has issued a warning that the unhealthy air conditions caused by smoke from wildfires in Canada will continue in the country for several days.
The current adverse weather conditions "will probably be hanging around at least for the next few days," said National Weather Service meteorologist Bryan Ramsey.
These unfavorable conditions are expected to continue unless there is a shift in wind direction or the wildfires are extinguished. Given the size and intensity of the fires, they are likely to continue for several weeks, Ramsey said.
The smoke from the wildfires is adversely affecting the lives of millions of people in Canada and the US East Coast, with the impact projected to continue until the weekend.
In response to the situation, Washington, DC Mayor Muriel Bowser ordered schools in the city to keep students indoors during breaks and cancel outdoor sports activities and field trips on Thursday.
Officials in the city of Philadelphia, Pennsylvania also took measures establishing shelters for individuals living on the streets who have been affected by the smoke.
New York Governor Kathy Hochul has described the worsening air quality as an "emergency crisis."
While the ideal air quality index should be 50, certain areas in New York recorded levels as high as 400 on Wednesday.
More than 400 wildfires are currently raging across various parts of Canada, resulting in the displacement of around 20,000 people.
The US has sent 600 firefighters and equipment to assist in Canada.