California’s Fire Season May Be Starting Early This Year

On May 2, the National Weather Service (NWS) issued a “red flag” fire warning for parts of Northern California, the first time such a warning has been issued in May since 2014, reports Elliott Almond for the San Jose Mercury News. The warning was triggered by a confluence of dry, hot conditions with strong winds, which were gusting up to 35 miles per hour in some areas, reports Maanvi Singh for the Guardian.

Just a few days after the warning was issued, temperatures were a full 15 degrees Fahrenheit above average for this time of year. The red flag warning and the fire-prone conditions signal that the most dangerous part of California’s now year-round fire season may have already arrived.

The conditions stoked a number of small fires including one in Big Basin Redwoods State Park, an area that burned during last year’s CZU Lightning Complex fires, reports Amy Graff for SFGate. Last week, the state fire agency, Cal Fire, was also fighting a 5,100-acre wildfire near San Diego, per the Guardian.

“It’s crazy, May and a red-flag warning,” Craig Clements, director of the Wildfire Interdisciplinary Research Center at San Jose State University, tells the Mercury News.

Unseasonably hot conditions are piling on to the aftermath of what has been an exceptionally dry year that has plunged much of California into drought. This ends up increasing the quantity of living and dead vegetation across the state that is dry enough to burn.

Speaking with SFGate regarding the Big Basin fire and others in the Santa Cruz Mountains, Cecile Juliette, a spokesperson for Cal Fire, says “the dry conditions and the very poor fuel moisture recovery over the last six or eight months and the lack of rain we’ve had and also the continued drought have put us in a position where our fuel moistures are very dry and we’re experiencing conditions that we would normally experience later in the summer in June and July and it’s only the beginning of May."

The early fire season follow closely on the heels a catastrophic fire season in 2020, which saw 4.2 million acres burned and 31 deaths, making it California’s worst wildfire season on record. There’s no way of knowing whether this year will exceed those grim totals, but 2021 is off to a fast start, with Cal Fire already responding to more than 1,300 wildfires that burned some 2,200 acres since January 1. Last year, Cal Fire had only counted 814 fires that scorched 1,056 acres by this time, according to SFGate.

A recent analysis by Matthew Cappucci of the Washington Post of 60 years of California climate and fire data finds climate change is expanding the Golden State’s fire season and compressing its traditional rainy season. For example, in Northern California's Mount Shasta, the dry season has grown by 22 days since 1979 and San Francisco’s dry season expanded by 14 days, according to the Post’s analysis. Interestingly, the Post reports that the overall rainfall during California’s winters hasn’t decreased, but it has started arriving later and dumping its water in shorter bursts, which ends up lengthening the fall fire season.

But this year, rainfall in Northern California has been abnormally low. Per the Mercury News, San Francisco International Airport currently at 37 percent of normal rainfall for the year while Oakland is at 40 percent, San Jose is at 43 percent and Santa Rosa at 37 percent of normal. Meanwhile, the Sierra Nevada snowpack is 59 percent of normal, which has implications for water allotments since it supplies nearly one-third of California’s water, according to the Mercury News.

Though none of these figures sound good, experts say there is still uncertainty in how it will all play out in the coming months.

“The parts of the state that have seen the most severe snow and rainfall shortages are the ones that you expect to see the highest fire risk,” Chris Field, climate scientist at Stanford University, tells Guardian. “But there are always lots of unknowns that determine the way in which the actual fire season will unfold.”

Alex Fox | | READ MORE

Alex Fox is a freelance science journalist based in California. He has written for the New York Times, National Geographic, Science, Nature and other outlets. You can find him at Alexfoxscience.com.