Why Are There So Many Wildfires in California?

It's fire season in California—and 2020 is already proving to be another record-breaker.

Wildfires are nothing new or anomalous in California—this is the state that experiences them the most. They occur naturally, every year starting around August and lasting through November, and they are “nature’s way of clearing out the dead litter on forest floors,” as Science magazine once put it. Once burned, that dead litter’s nutrients are absorbed back into the soil, helping to support and make way for new life. Make no mistake, though; what’s transpiring in California this year is extreme—Governor Gavin Newsom declared a state of emergency on August 18—and possibly too extreme to benefit the ecosystem, burning too far, wide, and long for it to bounce back. And we humans are mostly to blame. Below, we take a look at how and why.

Ignoring indigenous knowledge

As of this writing, 28 large groups of fires are raging in California, with 1.4 million acres already burned—and we’re just at the beginning of the season. How did we get here? Partly through our failure to follow indigenous practices of annual controlled burns—a way to help keep fires from raging out of control. In fact, state and federal governments actively suppressed both naturally occurring fires and tribal burning practices and, well, here we are. Such fire suppression “has only made California’s wildfire risk worse,” according to NPR. “Without regular burns, the landscape grew thick with vegetation that dries out every summer, creating kindling for the fires that have recently destroyed California communities.” This also allows invasive, fire-susceptible plants to move in, creating a never-ending cycle. Luckily, officials are starting to realize the error of their ways and are working with indigenous communities to restore controlled burning practices.

Climate change, part 1: Drought

The effects of man-made climate change are many and becoming ever more extreme. California suffered a devastating drought between 2012 to 2016—even longer in some regions—and this year has been similarly dry. As early as July, The Mercury News was predicting an intense fire season for Northern California especially, based on 50 percent less precipitation than average in the Bay Area over February and March. And it’s not just lack of rain that leads to dry and fire-prone vegetation; reduced snowpack in the Sierra Nevadas is also a danger—and this year it was down 54 percent from its historical average. This is what it feels like to be caught in a wildfire.

Climate change, part 2: Increased heat

Combined with drought, excessive heat creates a scenario in which the landscape becomes a tinderbox; and researchers are discovering that it’s not only the flames that have devastating consequences—the smoke from the fires is more dangerous than we realized. This year, California experienced a record-breaking, week-long heatwave in which temperatures climbed into the triple digits for back-to-back days and, more alarmingly, nights, reports CNBC; temps in Death Valley reached 130 degrees Fahrenheit (close to the highest temperature ever recorded in the state), and state-wide, rolling blackouts exacerbated the chaos even as they were meant to lessen the threat of sparking that could ignite even more fires.

Climate change, part 3: Increased humidity

It may seem entirely counterintuitive, but humidity, too, has played a role in California’s already-devastating fire damage, as UCLA climate scientist Daniel Swain explained to Vox. To wit: a tropical storm that was losing steam over the Pacific Ocean led to moisture-formed clouds that in turn led to intense but mostly rain-less thunderstorms that did nothing to mitigate the already high fire risk. Needless to say, intensifying hurricane season—which neatly overlaps with fire season—is also a major result of climate change.


Yes, lightning. This year has been unusual in this regard as well. In 2019, most fires in California are instigated by humans—anything from purposeful arson to fireworks gone awry to power line sparks, reported the San Francisco Chronicle. This year, though, lightning has been the all-too-frequent culprit. On August 18, NBC Bay Area reported that 53,000 lightning strikes hit the region in a three-and-a-half-day period, resulting in numerous fire sparks; one 48-hour period saw over 7,000 lightning strikes that were responsible for some 350 fires. Not surprisingly, the heat and dryness only exacerbated the whole scenario. Here’s more info you should know about lightning.

Climate change, part 4: Lengthened fire season

Yes, it’s hotter. Yes, it’s drier. And yes, storms are intensifying and increasing in number. But the period in which these things are happening is also becoming longer. And a longer fire season leaves plenty of room for more fires. In fact, Governor Newsom has declared that this season’s just-begun fire season is already 25 percent worse than the fire season in 2019. And there are many long months still to go.


They’re not causing the wildfires but they are making them a lot worse, and a lot more unpredictable. This year, California has experienced a rare and dangerous phenomenon: fire tornadoes, whose high winds—around 80 mph—have stoked the flames and made efforts to fight them close to impossible. “They can prevent air support, in the form of retardant-dumping planes and water-dropping helicopters, from flying,” according to an article in Popular Mechanics. And “gusts can pick up embers and carry them to other locations, sparking new blazes for firefighters to contend with.” Sound terrifying? It is.


  • Science Magazine: “Ecosystems could once bounce back from wildfires. Now, they’re being wiped out for good”
  • CalFire
  • Vox: “What makes California’s current major wildfires so unusual”
  • NPR: “To Manage Wildfire, California Looks To What Tribes Have Known All Along”
  • The Mercury News: “Fire season: Which parts of California face the highest risk this summer?”
  • CNBC: “Raging fires, a heat wave and coronavirus: California battles several crises”
  • The Washington Post: “Heat is turbocharging fires, drought and tropical storms this summer”
  • San Francisco Chronicle: “What Causes Wildfires?”
  • NBC Bay Area: “By the Numbers: Thousands of Lightning Strikes Hit California”
  • ABC7 News: “2020 California fire season is 25 times worse than 2019’s, Gov. Newsom says”
  • Popular Mechanics: “Why Are There So Many Fires in California?”

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Lela Nargi
Lela Nargi is a veteran journalist covering science, sustainability, climate, and agriculture for Readers Digest, Washington Post, Sierra, NPR, The Counter, JSTOR Daily, and many other outlets. She also writes about science for kids. You can follow her on Twitter @LelaNargi.