The winter’s deadly and devastating floods are a distant memory for many Californians. Now, summer dangers, fueled by climate change, are top of mind.

Across the U.S., wildfires have grown larger and more frequent since 2000. But California fires can quickly escalate to megafires or gigifires (fires that cover more than a million acres) in part because they have become more unpredictable, writes CalMatters’ environmental reporter Julie Cart.

There are several reasons for this: The West recently experienced the driest period in more than a millennium. About a third of coastal summer fog, which prevents big fires from scorching California’s coastal redwood forests, has vanished. And rising temperatures keep flames burning overnight, crucial hours when firefighters typically toil to get ahead of fires.

Julie reports that Cal Fire crews attempt to outmaneuver these erratic blazes with fire behaviorists, who use information from satellites, military flights, drones, radar, and AI models to try and predict future fire movements. Any data point can be crucial — from wind force and direction to the shape and height of slopes — to manage conflagrations.

These advances in technology could not come soon enough. Though the state’s three-year drought is over, Cal Fire officials warn that last winter’s unprecedented rain has resulted in lush vegetation that can serve as kindling for summer fires. And ultimately, trying to predict something so capricious as fire — no matter the technology available — is futile.

• Mark Finney, Missoula Fire Sciences Laboratory research forester: “Once you are in a position to have to fight these extreme fires, you’ve already lost. Don’t let anybody kid you, we do not suppress these fires, we don’t control them. We wait for the weather.”

To learn more about wildfires, check out this explainer. And read Julie’s award-winning “Trial by Fire” series on the post-traumatic stress experienced by firefighters.

Newsom Launches Heat Ready CA Campaign

Even without wildfires, Californians have to deal with the danger of extreme heat. In advance of the scorching wave this weekend, Gov. Gavin Newsom announced on Tuesday the launch of Heat Ready CA — a $20 million, two-year campaign to warn communities about extreme heat. The elderly, workers, and people who have disabilities or are pregnant are particularly sensitive to heat.

• Newsom, in a statement: “The impacts of climate change have never been more clear — the hots continue to get hotter in our state and across the West putting millions of Californians at risk.”

The San Francisco Chronicle also reports an uptick of snowmelt mosquitos, which are more aggressive, in the Sierra Nevada due to high temperatures, as well as a greater risk of summertime wet avalanches, which have so far claimed two lives this season.

By the way, it’s not just California that is dealing with extreme heat. The effects are showing up around the globe.

• Daniel Swain, a UCLA climate scientist, in his weekly YouTube office hours: “The Earth currently this week appears to be hotter than any week than we’ve observed since we’ve been recording temperatures.”

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