More than 400 forest fires are still active across the country, and most of them are out of control. Prime Minister Justin Trudeau said Canada is living through its “worst wildfire season” in recorded history during a briefing with journalists in Ottawa on Wednesday.

Wildfires are poised to burn more land than ever in Canada, with over 3.8 million hectares (9.4 million acres) scorched so far, according to the Canadian National Fire Database. That’s about double the size of New Jersey.

Ottawa, Canada’s capital, was shrouded in smoke again, and its air quality health index was rated 10+ or “very high risk” by the country’s weather agency. Sports events were canceled and officials warned older people and young children to avoid strenuous outdoor activity. Flights were still leaving Ottawa’s airport, but with a number of delays.

“People across the country are being affected,” Trudeau said about the air quality. “We’re seeing vulnerable people at risk, outdoor events cancelled, kids having to be kept inside at recess.”

Quebec is the source of fires that are responsible for the pollution over New York. The province is facing 150 active wildfires, according to the website of a Quebec organisation that tracks fire activity. The weather forecast gives cause for concern, as heavier rain isn’t expected until early next week in the northern part of the province and a low pressure system funnels Quebec smoke into the US.

“I want us all to be realistic and not put on rose-colored glasses,” Quebec Premier François Legault said in a press conference. More than 15,000 people in the province alone could be under evacuation orders in the next few hours.

So far, the impact on businesses in eastern Canada has mostly been limited to the mining sector. Due to a railway disruption in northern Quebec, Iron Ore of Canada has reduced operations and Champion Iron Ltd expects material delays in sales of its iron ore. Other firms have temporarily suspended exploration activities. An emergency order from the provincial government prohibits access to lands impacted by forest fires.