This is Ontario’s worst wildfire season, early estimates suggest. It’s not over yet.

Ontario’s season is the latest sign of what scientists have warned could be a new era of extreme wildfire activity in Canada. Climate change, driven by the burning of fossil fuels, contributes to longer wildfires season with more frequent stretches of heat and drought that leave forests primed to burn.

The vast majority of Ontario’s fires burned in the past 10 days. They have forced more than 1,800 people to flee their homes, destroyed several communities and sent plumes of noxious smoke across the province and beyond. All but one of the 13 evacuated communities are First Nations.

Dry conditions percolated for weeks in the north before severe thunderstorms swept across the region and delivered lightning strikes to the parched boreal forest. A scorching heat wave sent temperatures soaring around 15 degrees above seasonal, while winds fanned the flames.

“It’s just the perfect conditions to have those fires spread,” said Anabela Bonada, managing director of climate science at the Intact Centre on Climate Adaptation at the University of Waterloo.

The largest contributor to Ontario’s wildfire season has been the massive 3,188-square-kilometre fire north of Thunder Bay. If that fire alone was a season, it would be the 12th largest recorded in Ontario.

Recent rain and cooler days have helped firefighters make progress, but the hazard remains high and officials expect continued fire activity for the foreseeable future.

“There hasn’t been enough rain in the northwestern part (of Ontario) to really knock things down for the long term,” said Buchart, the fire weather specialist.

Into August, the forecast suggests much of northern Ontario could remain hotter and drier than normal. While conditions may not be as intense as what the region just experienced, “a complete reprieve is not really in the forecast,” Buchart said.

The preliminary area-burned estimates are compiled by the province’s wildfire agency and shared with Canadian Interagency Forest Fire Centre, a non-profit that co-ordinates firefighting resources across the country. Federal wildfire records — also known as the national burned area composite — date back to 1972 and are derived in part from high-resolution satellite images.

Thick smoke is one of the factors that make it hard for officials to develop precise real-time wildfire estimates. Satellite images will eventually help to identify any water bodies or unburned areas that may have been included in the initial tally.

This report by The Canadian Press was first published July 21, 2026.

Jordan Omstead, The Canadian Press

by The Canadian Press

This is Ontario’s worst wildfire season, early estimates suggest. It’s not over yet.

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