The Manhattan skyline is seen across the Hudson river past a pedestrian walking along the waterfront in West New York. (Photo by Leonardo Munoz / AFP)
The air quality in New York City improved to "moderate” overnight, according to data from the New York Department of Environmental Conservation.
People in the city who are "unusually sensitive” to particle pollution are still being advised to consider reducing or shortening their activity, according to an advisory on the website.
The level for Washington, DC is "unhealthy for sensitive groups”.
The Air Quality Index improved to 100 on a scale of 0 to 500 as of 2 a.m. ET, the data showed.
The reading reached the most serious "hazardous” level earlier in the week, as smoke from wildfires in Canada moved across the US Northeast.