Wildfire smoke tracker: Where the air pollution is headed next

The northeast of the United States is battling smoke from 400 wildfires raging across Canada which have burned more than 6 million acres and led to mass evacuations.

And it’s far from over: Canadian officials warned that this could be the country’s worst wildfire season on record.

Smoke has darkened skies and made it difficult to breathe in at least half a dozen states and large parts of Canada, including major cities like New York, Toronto, Ottawa, Washington DC and Philadelphia.

Live: New York’s Central Park clouded in haze from Canadian wildfires

In areas with “hazardous” levels of air pollution, public health officials were advising people to stay indoors and wear masks if outside.

Vulnerable populations including children, the elderly, and those with underlying conditions like asthma and heart disease, should particularly heed the warnings.

Which states and cities are affected by smoke?

At least thirteen US states have air quality alerts issued in places, impacting an estimated 115 million people.

Among the worst-affected locations were major cities like New York, Washington DC, Philadelphia, Detroit, Jersey City, and New Haven.

New York was ranked number one for the worst air quality in the world at 2pm local time on Wednesday. At one point, the Air Quality Index (AQI) - used by public officials to measure air pollution - reached above 350, on a scale that runs from 0-500. The air pollution level is currently “hazardous”.

In a sign of how extreme conditions are, New Delhi - a city where people live under the threat of heavy air pollution much of the year - was in second place with an AQI of 190. Toronto is in fourth place with AQI 160.

Which direction is the smoke moving?

Thick smoke continued to push south from Canada through the east coast on Wednesday afternoon.

People were being warned to take extra precautions due to less visibility, a drop in air quality and the unavoidable strong “campfire” smell.

In New York, unhealthy levels of air pollution will last until around Thursday morning but the smoky conditions could continue beyond that.

During a press conference on Wednesday afternoon, New York governor Kathy Hochul warned that the smoke cloud was moving westward.

“We’re expecting over the next couple of days they’re going to be heading westward,” she said. “Buffalo and western New York are going to be in trouble tomorrow.”

The governor added smoke above the Empire State could clear by the weekend.

The fires have been burning for weeks. Why is it smoky now?

The fires in Quebec province started this weekend and blazes in Nova Scotia, on the Atlantic Coast, began last month.

A storm system off Canada’s east coast is pushing the smoke south over the United States. This weather pattern is expected to continue until at least the weekend.

The National Weather Service said that while the wildfires in Canada remain “large, uncontained, and active, they will likely continue to generate smoke”.

“So in the next week or two at the very least, a lot will be determined by the wind direction and where that causes the smoke to spread,” the agency added.

The weather pattern will remain much the same through this weekend. A stalled low-pressure system near Maine and the Canadian Maritime Province means northerly winds from the fires in Quebec will direct the smoke into portions of the east coast, NWS noted.

This article is being updated