The Weather Network says Canadians should brace for a fall that starts with dramatic swings, mellows into an unusually mild stretch, and could end with an abrupt and wintry turn.
Record-breaking heat in British Columbia and early blasts of cold in Central and Eastern Canada have already marked a turbulent start to the season. But according to senior meteorologist Doug Gillham, most of Canada will soon “hit the pause button” on extremes, with warmer-than-normal conditions expected to dominate from mid-September through October. The quieter middle of the season will mean fewer storms and more opportunities for Canadians to enjoy fall foliage and outdoor activities.
That reprieve is expected to fade by November, when storm activity and colder air will return, setting the stage for a more typical late-fall and a strong start to winter. Precipitation will likely be near normal across most of the country, though Northern Canada, the B.C. coast, and parts of northeastern Ontario through central Quebec and Labrador could see more rain than usual. The northern Prairies, which endured drought conditions over the summer, may welcome the near-normal precipitation outlook.
Atlantic Canada remains the biggest uncertainty. While forecasts suggest fewer fall storms, the ongoing hurricane season could deliver surprises, with late September and early October posing risks depending on storm tracks. Cooler North Atlantic waters may weaken systems before landfall, but Gillham warned that “it only takes one system to have a significant impact.”
Ontario and Quebec, after a chilly start to September, are forecast to enjoy warmer-than-normal stretches before storm activity ramps up in November. The Prairies should also see extended mild periods interrupted by brief cold snaps before a colder, stormier pattern arrives late in the season. Western Canada will continue to battle wildfire smoke for a few more weeks until the rainy season begins. While B.C.’s record heat will ease, warmer Pacific waters could fuel storms capable of bringing heavy rain, though Gillham hopes for beneficial rainfall and alpine snow rather than flooding.
Those same warm Pacific waters are pushing the jet stream northward, explaining the forecast for a milder mid-season. But as the jet stream shifts south in November, Arctic air and storm systems will follow.
Across the North, temperatures are expected to be above normal, with Nunavut facing higher precipitation than usual. Overall, climate change is reshaping what “normal” means—average autumn temperatures across Canada have climbed by 2.4 degrees since 1948.
“This fall will feel like a rollercoaster that slows down in the middle, but we can’t hold off winter forever,” Gillham said.