Extended California heat wave brings extreme health, fire risk; power shutoffs likely

A man takes in the view from Hilltop Park in Signal Hill, Calif. on a sunny afternoon. (Wally Skalij/Los Angeles Times/TNS)

LOS ANGELES — Authorities are warning of extreme health and wildfire risks across California this week, as the longest heat wave of the year is set to kick off Tuesday, bringing triple-digit high temperatures with little cooling, even at night, to the vast majority of the state.

“This is really just a long-duration heat event that will provide little to no overnight [temperature] relief,” said Antoinette Serrato, a National Weather Service meteorologist in Hanford. The prolonged heat wave is expected to bring dangerous temperatures throughout the Fourth of July holiday weekend in many areas — particularly across Northern California, the Central Valley and southwestern deserts — lasting through early next week, she said.


Much of Los Angeles County’s inland valleys and mountains, including the San Fernando Valley and San Gabriel Mountains, are included in an excessive heat watch from Wednesday through Sunday, when high temperatures from 95 to 110 degrees are expected. However, most of the coastline is expected to be largely spared from the worst of the heat. Downtown Los Angeles, Orange and San Deigo counties were not yet included in any heat advisories.

On Tuesday, a combination of excessive heat is expected to overlap with a red flag warning — an alert for extreme fire weather — in parts of the northern Bay Area and Sacramento Valley, raising concerns about potential fire starts. Low humidity, winds up to 30 mph and hot temperatures could create the perfect storm for wildfires, officials warned.

Pacific Gas &Electric Co., the state’s largest utility, announced that power cuts were likely for Tuesday in some Northern California counties, “due to high winds and dry conditions,” part of its safety shutoff program that aims to reduce the chance for accidental fire ignitions. The counties that could be affected are Colusa, Glenn, Lake, Napa, Shasta, Solano, Tehama and Yolo, according to the utility’s website.

The California Governor’s Office of Emergency Services also announced Monday that it had pre-positioned fire engines and personnel across the state, given the extended heat wave and wildfire threat.

“A combination of strong wind, low relative humidity, and hot temperatures can contribute to extreme fire behavior,” the National Weather Service wrote in its red flag warning for the Sacramento Valley and North Bay interior mountains, lasting from Monday night through Wednesday.

But weather officials say the greatest concern this week comes from the extreme, extended heat, which is expected to bring major health risks.

“As we start moving into the weekend, there are a lot of areas… that are going to see extreme heat risk,” Serrato said, referencing the weather service’s new heat risk tool. “Overnight low temperatures will be around 70 degrees for a lot of areas, maybe even higher.”

From Northern Humboldt County to inland San Diego County — and practically everything in between — the National Weather Service has issued an excessive heat warning this week, in most areas beginning Tuesday and lasting at least until Friday, in some areas as long as Monday.

Leave a Reply

Your email address will not be published. Required fields are marked *


By participating in online discussions you acknowledge that you have agreed to the Star-Advertiser's TERMS OF SERVICE. An insightful discussion of ideas and viewpoints is encouraged, but comments must be civil and in good taste, with no personal attacks. If your comments are inappropriate, you may be banned from posting. To report comments that you believe do not follow our guidelines, email hawaiiwarriorworld@staradvertiser.com.