Heat wave west: Phoenix hits 118°F as 10 deaths confirmed

Phoenix recorded 118°F on Friday as an extreme heat wave engulfed the Western United States, killing 10 people across Arizona and Nevada.

The National Weather Service issued excessive heat warnings for 40 million people from California to Colorado through Monday.

Temperatures reached levels not seen since 2020. Power grids strained under record demand. Hospitals reported surging heat-related admissions.

The heat dome parked over the region broke 40 daily temperature records, the National Weather Service reported. Las Vegas touched 115°F. Palm Springs hit 120°F. Denver reached 102°F.

Meteorologists linked the event to climate change. “This intensity would have been virtually impossible without global warming,” said Daniel Swain, climate scientist at UCLA. He told reporters the heat dome’s strength matched the 2021 Pacific Northwest event that killed 800 people.

Phoenix firefighters responded to 85 heat emergency calls on Friday alone, Captain Todd Keller said. Ten people died in Maricopa County since Tuesday, the medical examiner confirmed. Victims ranged from 37 to 82 years old.

Nevada hospitals admitted 47 people for heat exhaustion, state health officials reported. Two died in Las Vegas. Temperatures on sidewalks reached 170°F, burning people who fell.

California’s grid operator called voluntary conservation as electricity demand neared 47,000 megawatts. The system held but came within 3,000 megawatts of triggering rolling blackouts, said Elliot Mainzer, CEO of California ISO.

“We’ve added 6,000 megawatts of battery storage since 2020,” Mainzer told reporters. “That prevented widespread outages.”

Parks closed across the Southwest. Phoenix shuttered 14 hiking trails. Death Valley National Park stopped allowing private vehicles after 10 a.m. A 71-year-old man died while hiking in 119°F heat on Wednesday, park officials confirmed.

Cooling centers opened in every major city. Phoenix libraries extended hours. Las Vegas converted convention space. Los Angeles stationed 60 cooling centers, Mayor Karen Bass announced.

Border Patrol agents rescued 42 migrants in the Arizona desert over three days, spokesman Aaron Heitke said. One woman died near Tucson. Smugglers left behind groups without water, agents reported.

Agricultural losses mounted. California’s Central Valley hit 112°F, damaging tomato crops. “We’re seeing blossom drop,” said Roger Isom, president of the California Cotton Alliance. He estimated $50 million in losses.

Wildfire risk spiked after 3 years of wet weather. California recorded 11 new fires on Friday. Nevada’s Pine Grove fire burned 2,400 acres. Red flag warnings covered 6 states.

Background

The Western United States experienced increasingly frequent extreme heat events since 2000. Climate change raised average regional temperatures 2.3°F above pre-industrial levels, according to NOAA data.

Summer 2021 brought the worst heat wave on record to the Pacific Northwest. Temperatures reached 116°F in Portland. 800 people died across Oregon, Washington and British Columbia. The event prompted cities to develop heat action plans.

Phoenix recorded 53 days above 110°F in 2020, breaking previous records. The city created the nation’s first heat readiness office in 2021. It hired a chief heat officer to coordinate response.

Power grids failed during California’s 2020 heat wave. Rolling blackouts affected 800,000 homes for the first time since 2001. State officials later required utilities to add 11,500 megawatts of storage by 2026.

What’s Next

Temperatures will gradually decrease through Wednesday as the heat dome shifts east, National Weather Service meteorologist Sarah Rogowski said. Phoenix should drop to 105°F by Thursday. warnings will likely end Tuesday night.

Arizona officials plan to review heat response protocols after this event ends, Governor’s Office spokesman Ben Scheel told reporters. California regulators will assess grid performance next month.