The darkness of night has traditionally signalled reprieve for wildland firefighters, but a new Canadian study shows that’s changing, and drought is the driving force.
“We have fire growth models, and they handle the day really well most of the time, and that’s usually the most important part. But they don’t really do well at night,” says Mike Flannigan, one of the study’s co-authors in British Columbia. The study, published Wednesday in the peer-reviewed journal Nature, suggests that is an increasingly risky bet as climate models predict summers will get hotter and drier, conditions that Flannigan describes as a “powder keg” for wildfire.
The study used wildfire records and satellite data to examine more than 23,500 blazes across North America from 2017 to 2020. The researchers identified 1,095 overnight burning events associated with 340 wildfires and found the vast majority spanned at least 10 square kilometres. That’s significant, Flannigan says, because it’s a crucial time for rallying firefighting resources with the goal of containing flames before they spread.
“That day, you can say, ‘this is a high likelihood of burning through the night,’ and prepare accordingly,” Flannigan says of the new modelling.