CNN
—
An extremely dangerous and unusually long heatwave is intensifying and spreading across the West Coast – and there will be no letup for several days.
California, Oregon, Washington, Nevada and Arizona are bracing for possible wildfires, opening cooling centers and warning residents to stay indoors and hydrate as the relentless heat wave brings sweltering temperatures of up to 100 and 110 degrees Fahrenheit — with highs possible in the 120s in the desert southwest.
And it only gets worse.
Death Valley, California, could reach 50 degrees Celsius on Sunday or Monday, setting a new daily record for those dates. Las Vegas, Nevada, could also surpass its all-time high of 47 degrees Celsius on Sunday or Monday.
“Confidence is increasing that this potentially historic heat wave will last for several days,” the National Weather Service in Portland warned, adding that the risk of heat-related illness would increase significantly.
Extreme heat is a leading cause of weather-related death in the United States, claiming hundreds of lives each year, according to the National Weather Service.
In San Jose, California, a homeless man died Tuesday due to extreme heat, Mayor Matt Mahan said. The man was 69, according to mayoral spokeswoman Tasha Dean, citing information from the Santa Clara medical examiner’s office.
The same day, a 10-year-old boy died in Arizona after experiencing a heat-related emergency while hiking with his family in South Mountain Park and Preserve, the Phoenix Police Department said.
“This is a DANGEROUS situation, especially for sensitive populations,” the National Weather Service in Los Angeles said, reminding residents to drink plenty of water, stay in the shade, wear light, loose clothing and never leave anyone in a car.
View this interactive content on CNN.com
Saturday will likely be the hottest day of this prolonged heat wave, with high temperatures of 110 degrees Fahrenheit becoming common in California, outside of coastal areas and higher elevations, the National Weather Service said.
“This level of heat in parts of the Mojave Desert and Sacramento/San Joaquin Valleys of California could pose a risk to anyone if proper heat safety precautions are not followed,” the weather service said.
Nationwide, nearly 140 million people remain under heat alerts — mostly in Western states, where the heat wave is expected to last through the middle of next week.
Parts of Oregon will see triple-digit temperatures Friday, and the heat could last up to five days with little relief overnight, the National Weather Service in Portland said.
A state of emergency has been declared in Multnomah County, Oregon’s most populous county, for this weekend as temperatures are expected to soar.
“I am especially concerned for the thousands of people who will be traveling to music festivals and sporting events this weekend,” Multnomah County Health Officer Dr. Richard Bruno said in a news release. “They will be spending a lot of time outdoors, may have little access to shade and water, and may not recognize the risk.”
View this interactive content on CNN.com
Bruno said the region has seen few hot days so far this year and residents’ bodies have yet to acclimatize to the heat.
A previous heat wave that ravaged Oregon in 2021 left dozens dead. Electrical equipment failed in the heat, triggering power outages for tens of thousands of people as temperatures topped 100 degrees Fahrenheit.
While this heat wave is not expected to be as intense as the one in 2021, forecasters are concerned about its long duration, said meteorologist Noah Alviz of the National Weather Service in Portland. “Temperatures in the 90s, even 104 degrees for four to five days, that’s very unusual for this location,” Alviz told CNN.
“Triple-digit heat will extend northward into the Pacific Northwest and parts of the central Great Basin, with highs reaching 90 and 100 degrees Fahrenheit,” the National Weather Service said. “The duration of this heat is also a concern, as above-average scorching temperatures are expected to persist through next week.”
More than a dozen temperature records were broken or tied Thursday, including in several California cities. Palmdale hit 110 degrees and Madera hit 109 degrees.
View this interactive content on CNN.com
Extreme heat, combined with high winds and low humidity, means that any wildfire that does break out will spread quickly through already dried-out vegetation.
Red fire warnings are in effect across the West, including in the area of the Thompson Fire, which has burned more than 3,700 acres in Butte County, California, since it was reported Tuesday. The fire, which was 46 percent contained as of mid-morning Friday local time, has forced thousands to evacuate and prompted more than 2,000 firefighters to battle the blaze in extreme heat in the Oroville area.
According to Chris Peterson, a spokesman for the California Department of Forestry and Fire Protection (Cal Fire), 11 firefighters were injured in the blaze, including eight suffering from heat-related illnesses. Twenty-six structures were destroyed by the fire and more than 4,000 are at risk.
The state is experiencing an active fire season, with more than 145,000 acres burned so far in 2024, compared to 7,812 acres burned at the same time last year, according to Cal Fire.
There are currently nearly two dozen active wildfires of varying sizes burning in California, and the Thompson Fire is among the largest, according to Cal Fire.
“We’re seeing fires from the coast of San Diego all the way up to the foothills of Butte,” Cal Fire Deputy Director Nick Schuler told CNN on Wednesday. “Our firefighters are battling fires all across California and are often on the ground for more than 24 hours. They’re facing challenging conditions.”
A wildfire in Mariposa County, California, called the French Fire, prompted evacuation orders Thursday night. The blaze has burned more than 800 acres just northwest of the small community of Mariposa, outside Yosemite National Park, and was 5 percent contained as of Friday morning.
A stay-at-home order has been issued for two hotels near Yosemite National Park due to the wildfire, the Mariposa County Sheriff’s Office said Thursday night.
California Gov. Gavin Newsom declared a state of emergency in the Thompson Fire area on Wednesday, opening the door to additional resources, including the possibility of mobilizing the California National Guard to assist.
And in central Washington state, fireworks sparked an active wildfire called the Balsam Root Fire early Friday morning, according to Wenatchee Valley Fire Chief Brian Brett.
The fire is raging in Wenatchee, about 150 miles (240 kilometers) east of Seattle. The fire is currently about 250 acres (100 hectares) and 30 percent contained, Brett told CNN. A Level 3 evacuation alert is in effect for about 150 homes. Residents affected by the advisory are asked to leave immediately.
The department had previously reminded residents that “private fireworks are prohibited in most of Chelan and Douglas counties.”
According to the National Fire Protection Association, fireworks started an estimated 31,302 fires in 2022.
Stephen Lam/San Francisco Chronicle/Getty Images
A Cal Fire aerial tactical aircraft releases a puff of smoke while guiding a drop of fire retardant on the Thompson Fire in Oroville, Calif., Wednesday.
As the West swelters, oppressive heat and humidity will begin to move eastward toward the Mid-Atlantic and Southeast by the end of the week.
“Warm overnight temperatures of 70 to 80 degrees Fahrenheit (21 to 27 degrees Celsius) will provide little relief, creating a dangerous situation for those without access to adequate cooling,” the National Weather Service said.
New heat alerts are now being issued for southeast Texas, far south Florida and parts of the Southeast into the mid-Atlantic, where highs will range from 95 to 105 degrees. Cities including Houston, Miami, Atlanta, Raleigh and Washington, D.C., will feel the heat.
Heat index values – how the air feels on the human body – will range from 100 to 115 degrees in these areas.
“A cold front moving into the southern Plains is expected to bring cooler, below-average temperatures to Oklahoma, much of north/west Texas and south-central Texas by Friday,” the weather service said.
