Smoky haze from Canada wildfires triggers New York flight chaos

Health alerts in dozens of states as New York City air quality rated worst in world

Hundreds of flights were delayed and dozens of public events cancelled across the eastern United States on Thursday as smoky haze caused by Canadian wildfires led to hazardous pollution.

Health officials in more than a dozen states warned millions of residents that spending time outdoors could cause respiratory issues due to the high levels of fine particulates in the atmosphere.

Forest fires continue to burn across Canada, which is enduring its worst-ever start to wildfire season. Thousands have been forced from their homes and about 9.4 million acres have already burned, roughly 15 times the 10-year average.

The southward drift of smoke is likely to continue until Sunday, when a new storm system shifts the direction of prevailing winds and brings a chance of rainfall.

A cyclist rides under a blanket of haze partially obscuring the US Capitol in Washington on Thursday (AFP/Getty)

In the US, air quality alerts were extended from New England to South Carolina, as well as parts of the Midwest, including Ohio, Indiana and Michigan.

New York City’s air quality was 183 on the air quality index scale, making it the worst in the world, according to monitoring service IQAir.

At least 415 flights across the country were delayed and another eight were cancelled. New York’s Newark and La Guardia airports were among the worst hit.

In Washington, the National Zoo was closed, while the Nationals baseball team postponed its afternoon home game.

A Delta plane takes off into a smoke haze from Washington National Airport in Arlington, Virginia (AFP/Getty)

The White House also postponed its Pride Month event, which had been expected to be the largest such White House celebration for LGBT+ people in history. It was rescheduled for Saturday when the air quality was expected to improve.

It is the worst case of wildfire smoke blanketing the region in more than 20 years, according to private forecaster AccuWeather.

Large areas of Michigan are also under red flag warnings due to dangerous fire weather conditions in both of the state’s peninsulas.

Reuters and Associated Press contributed to this report.