Wildfire in the Bay Area: Are We at Risk of a Megafire like L.A.’s?

In January of 2025, wildfires swept through 57,000 acres of Los Angeles, impacting thousands of lives. These fires burned an area almost twice the size of San Francisco and four times the size of Manhattan. Many of us had friends or family who were impacted by the devastation. It was a powerful reminder of how quickly wildfire can put our families, homes, ecosystems, and communities at risk. And while it’s perfectly valid to despair in these times, it’s heartening to know that, across California, conservation experts are preparing, adapting, and making our region more resilient in anticipation of the next megafire.     

Forest managers for POST and our public agency partners in the Santa Cruz Mountains are now fighting fires in advance by constructing shaded fuel breaks and using low-intensity, carefully planned, prescribed burns to help reduce the fuel that has accumulated over decades. Still, wildfires are a part of nature, and as more houses are built “among the trees” in the wildland-urban interface and our weather becomes more extreme, so do the fires that naturally occur. 

Could a megafire like that happen in the Bay Area? I spoke with POST’s Forest Health Program Manager Brian Homberger, who also happens to be a volunteer firefighter in Santa Cruz County, to get some answers.

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Missed our live webinar? You can now watch the full recording below. Join Brian as he explores the relationship between wildfires and forest health in the Bay Area and beyond.

COULD A MEGAFIRE HAPPEN IN THE BAY AREA?

How similar or different is the Bay Area from the area that burned in L.A.?

BH: It’s definitely a lot hotter and drier in Southern California, and more of a desert and chaparral ecosystem, making for a much more flammable landscape. The parallel is that the winds they experienced, the Santa Ana winds, are a lot like the Diablo winds in the Bay Area. The Diablo winds come from the eastern Sierra toward the ocean and are extremely hot and dry. What we are seeing in both areas is the result of climate change, with more extreme weather, longer droughts, and hotter average temperatures. 

What are the factors that set up a megafire?

BH: There are a few different factors. One is that more people are living in the wildland/urban interface. Previously, people were concentrated in urban or suburban areas, but we’re seeing a lot more people building their homes in very flammable, fire-adapted landscapes. 

Another issue is increased fuel loading and the buildup of vegetation. In historically fire-adapted landscapes, the plants have evolved to have fire at regular intervals. With the absence of regular, low-intensity fire, we get a tremendous buildup of plant and vegetation in the understory. Additionally, the colonization of California by Europeans caused a departure from thousands of years of “good fire” on the landscape. This change from Indigenous burning practices ramped up in 1850 when the U.S. government outlawed intentional burning, including cultural burning by Native tribes. As a result, we have forests choked with vegetation, resulting in massive buildup of flammable fuels. 

That is coupled with climate change’s more extreme weather patterns: longer droughts mean more stressed-out forests. One of the predictors of how bad a fire season is going to be is if you had a previous wet winter. A wet winter creates a big flush of new growth in flashy fuels like grasses, and, if there is a following dry and hot summer, the grass dries out and gets really flammable. 

What caused the L.A. fires to spread so fast?

BH: There are three main factors that influence wildfire spread. The first is topography, so the way the terrain is oriented. Is it a valley? Is it a canyon? Is it a ridgeline? 

The second factor is fuel type, so, is it chaparral, grassland, or forest, and are you in a wildlife/urban area or a suburban area? 

And the third factor is weather. I think what made the Southern California fires so intense was mostly the extreme weather and high winds. When you’re in a really dry, really intense wind situation like they were, you’re going to see rapid fire expansion. The fire crews were trying as hard as they could, but with a wind like that, with gusts of 80 to 100 miles per hour, there’s not a lot you can do. It’s pretty much an ember storm of millions and millions of embers, and the rate of spread of the fire is the rate of spread of the wind. 

So, how do I know if my house is at risk?

BH: We live in a really diverse region with many different localized communities. Just in the Santa Cruz Mountains, we have coastal areas, steep mountainsides, suburban areas, urban areas, and farming communities, so there’s a lot of variability. Whether you live in Santa Clara, San Mateo, or Santa Cruz County, checking recommendations of your local fire safe council or local fire district is really key. Your local fire marshal or fire department can also come out and do home inspections with you. Each house is different, each neighborhood is different. 

This is also a neighborhood- and community-wide effort. If you prepare your house, but your neighbor doesn’t do anything, then you could still have unfavorable outcomes. So, there are local fire safe councils in Santa Cruz, Santa Clara, and San Mateo counties and cities and towns like Bonny Doon. And they all take a specific community-wide approach.

If there is a megafire, how do I know if I should evacuate?

BH: I would say, heed your local warnings. Material things are replaceable, but human life is not. It’s a gut-wrenching decision. It’s really complicated. Everyone’s in a different situation, but, if folks say to evacuate, please evacuate. It’s important because they’re fighting the fire and you don’t want them to stop fighting the fire to save someone in distress. It puts more people in danger. Heed your local evacuation warnings. If you are under an evacuation order, please evacuate. 

Anything else?

BH: Sometimes disasters go hand-in-hand. As we saw in 2020, the  CZU Lightning Complex fire occurred during COVID, and that complicated things. These things don’t always happen one by one. Be prepared, both mentally and with your family and loved ones. Where are we going to go? How are we going to meet? Do you have pets? Do you have medications? Who can we call outside of the area? Who can help coordinate? In the moment, you have a lot of adrenaline, so it’s important to pre-plan and think through what you’re going to do.

That, conveniently, brings us to the question of how do we prepare for a fire? Check out the rest of my conversation with Brian about preparing your family and your home for fire here and sign up for emergency alerts for your county: San Mateo, Santa Clara, Santa Cruz.

About Brian Homberger

Brian Homberger is originally from Central Florida, where he earned a degree in Biology from the University of Central Florida. He has been living in California for the past 14 years and previously worked for the US Forest Service in the Tahoe Basin as a wilderness ranger and on a backcountry trail crew. Brian is a certified ISA arborist and active EMT and has been a volunteer firefighter with Santa Cruz County, Company 32, Bonny Doon for the past six years.