The Bald Ridge wildfire exploded across the slopes above Summerland last Friday, consuming 50 square kilometres in barely three hours and triggering the largest evacuation order the southern interior has ever seen. By Monday the blaze had reached 156 square kilometres, blanketing much of southern British Columbia in smoke and leaving more than 22,000 residents displaced under a provincial state of emergency.
"It was absolutely shocking to see that fire go from an ignition and then spread to a thousand hectares within an hour or so, 5,000 overnight and 10,000 within 24 hours," said Lori Daniels, Kerner Chair at the Centre for Wildfire Coexistence at the University of British Columbia. "I think that's the most rapid fire spread we've ever witnessed in the southern interior of B.C., for sure."
Wind channelled through valleys drove downhill run
Fire behaviour analysts point to a rare combination of topography and meteorology. Cliff Chapman of the B.C. Wildfire Service described conditions on Saturday as "explosive" and said the service had never faced anything comparable. Instead of climbing upslope as fire normally does, the flames were shoved downhill by powerful westerly winds that accelerated through mountain valleys toward Okanagan Lake.
"The winds in this case were coming very strongly from the west and it pushed that fire down the hill and through the valley," Daniels explained. "Because of the shapes of the mountains there, it's kind of channelled that wind and the fire. So it came down through the valley and then it kind of exploded out as it got closer to Okanagan Lake." She characterized the gusts as approaching low-grade hurricane force.
Environment Canada recorded sustained winds of 20 kilometres per hour gusting to 40, but Tanzina Mohsin, associate professor of climate technology at the University of Toronto, said the fire itself likely amplified those speeds. "When there is a heated surface, what happens is the wind speed rises. If there is a forest area where the initial wind is 20 to 30 km/h, but immediately when the fire spreads and the surface becomes warmer and warmer, this wind can reach as high as 40 to 50 km/h with dust," she said. "This could be one of the causes of the Summerland fires spreading so quickly."
Multi-year drought created tinder-dry fuels
The wind event arrived on a landscape primed by years of moisture deficit. Daniels noted that British Columbia has endured extremely long, multi-year droughts over the last decade, drying ecosystems to a degree that turns ordinary lightning storms into mass ignition events. "When you get the heat domes, we've seen them in different parts of Canada and it's a pattern all across Canada. You get a heat dome, record-breaking temperatures, very dry conditions, and then what happens is when that heat dome and that weather system breaks down, it brings with it very windy, turbulent conditions that create the thunderstorms and the lightning," she said. "If you don't get a bunch of rain, but you get thunder and lightning on top of drought, you have the prime conditions for literally tens to hundreds of fires to be ignited simultaneously."
Katrina Eyvindson, associate professor and departmental chair of geography and environment at Western University, added that a low snowpack this year left fuels exceptionally dry. "Temperatures are high and there has been little rain making fuels particularly dry. Dry fuels make it easy for fires to start easily and spread quickly," she said.
The national picture reinforces the regional data. Natural Resources Canada has recorded 620 wildfires across the country so far in 2026 and links the escalation to "record high temperatures and widespread drought conditions across the country." Kent Moore, atmospheric physics professor at the University of Toronto, said the Summerland episode carries a warning for every province. "The situation in northwestern Ontario or Nova Scotia or Quebec is different, but all these areas are warming and they have different types of forest practices, different types of forests and things, but I think it's just a warning that our climate is changing and that means that things that were quite rare before, like wildfires are becoming more common," he said.
Daniels argued the response must shift from emergency reaction to societal adaptation. "If we have forest and trees near us now in Canada, people in the country are susceptible to evacuations and wildfire effects. It's really having people understand how vulnerable we are and really choose to make those changes. We really need to approach this as an all of society problem and an all-of-society solution."
Based on reporting by Global News.