How Unusual Is an Explosive Wildfire in January? And Can It Happen in the Bay Area?

Wildfires in California are common. Destructive ones are increasingly common now, too. But how common is a serious wildfire in Southern California in January?

Historically, the area’s wildfire season ran from May to October, according to the Western Fire Chiefs Association. But that season has grown longer as human-caused climate change is making landscapes hotter and drier, and a century’s worth of fire suppression has built up fuel and primed forests to burn.

Still, enormous wildfires like those wreaking havoc in Southern California are far from the norm.

“Large fires in January are exceedingly rare because the region nearly always receives a fire-season-ending rainfall event by the end of the year,” said Crystal Kolden, a fire scientist at UC Merced. “This is a very novel event.”

Several factors set the stage for the deadly wildfires in Southern California: massive vegetation growth from past wet winters that dried out in the blazing summer, a winter where the rains have yet to come, and extreme Santa Ana winds reaching 100 mph in some places.

“Unfortunately, people don’t tend to think of winter as fire season, but in California, fire season is any time it is dry enough, and there is fuel,” Kolden said. “The Santa Ana event just provided the blowtorch that makes the fires uncontrollable, and unfortunately, we will not see containment until after the winds die down later this week.”

Fires in densely populated areas like those burning in Los Angeles can and have occurred in the Bay Area. The 1991 Tunnel Fire in the Oakland and Berkeley hills killed 25 people and destroyed nearly 3,500 structures, and the 2017 Tubbs Fire in Santa Rosa left 22 dead and obliterated almost 6,000 structures. Both of those fires ignited in October, though.

“California is naturally adapted to fire, and it’s a part of our natural ecosystem,” said Michael Gollner, a researcher and fire expert at UC Berkeley.

While the conditions fueling Southern California fires are a perfect storm of dry fuels, warm weather and high winds, Gollner said all of those factors are a part of Northern California’s climatology, too, and they “can and will line up someday up here again.”

John Abatzoglou, a climatology professor at UC Merced, said it’s likely more common for those conditions to come together in Southern California than in the northern part of the state, however.

“In the Bay Area, the rainy season typically starts quite a bit earlier than in Southern California. And Southern California then has just that many more opportunities for dry conditions to collide with Santa Ana winds and arid ignitions,” he said. For the Bay Area, “the risk is there, but it’s certainly less.”

Kaitlyn Trudeau, a researcher at the nonprofit Climate Central, said there is no longer a fire season, and people need to adjust accordingly.

“What’s important is that people understand that these risks exist at all times of year,” she said. “There’s not a particular span of months where you don’t need to worry about it.”

Trudeau spoke with KQED just minutes after seeing an image of her grandfather’s charred-out home for the first time. It burned in the Eaton Fire this week, but her grandfather was safe.

“It’s going to become increasingly difficult to prepare for the future by looking at the past,” said Trudeau, “because we really haven’t seen what we’re going to be seeing in the future with increasing carbon pollution.”