In pictures: Canada's wildfires blanket millions in sepia smoke

In pictures: Orange skies and wildfire smoke loom over the World Cup final

As thick smoke settles in over major cities, Canada recorded the worst air quality in the world.

Canadians and some in the United States are being urged to stay indoors as wildfires continue to burn, creating chaos and tanking air quality across Canada and parts of the US, where the FIFA World Cup final is due to be played early next week.

Canadian authorities say crews are currently battling 110 out-of-control blazes, as more than 700 others continue to burn in remote areas. While not threatening major cities, the fires have burned 1.9 million hectares of land and are encroaching on smaller towns, prompting evacuation orders.

Smoke from the fires has blackened skies in Ontario and north-eastern parts of the US, prompting officials in both countries to cancel public events and issue health warnings.

In Ontario's capital Toronto — Canada's largest city — residents awoke to hazy, orange skies.

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Officials have closed public pools, cancelled summer holiday programs and closed the official FIFA Fan Festival that had been planned to take place before the World Cup semi-final match between England and Argentina.

On Thursday, Swiss firm IQAir said the Canadian city recorded the worst air quality of any major city in the world, beating New Delhi and the Democratic Republic of Congo's capital Kinshasa.

Nearby, New York City's air quality ranked fifth-worst in the world. Authorities there have warned residents they "may see visible smoke and hazy skies across the state and spikes in smoke-related pollution".

The US National Weather Service said the smoke could linger into the end of the week.

"We probably haven't seen the worst of it yet for New York City. We probably haven't seen the worst of it yet for the Great Lakes and upstate and New England yet either," Dan Westervelt, Lamont associate research professor at Columbia University, told Reuters news agency.

The smoke settled on the city just days before neighbouring New Jersey is scheduled to host 80,000 people at an open-air stadium for the World Cup final on Monday morning AEST.

Another 50,000 are planning to watch the game from Manhattan's Central Park.

Pennsylvania, Connecticut, Massachusetts, Maine and New Hampshire have all experienced worsened air quality.

The fires burn against the backdrop of a record-smashing North American heatwave, which has seen temperatures soar into the 40s in parts.

While significant, Canadian authorities say the current fire season has been significantly less dangerous than those that ravaged the country in 2023, when 18 million hectares burned.

— With additional reporting by Reuters news agency and Agence France-Presse.

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