Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on the day's biggest business stories

Subscribe to Axios Closer for insights into the day’s business news and trends and why they matter

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Stay on top of the latest market trends

Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sports news worthy of your time

Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tech news worthy of your time

Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Get the inside stories

Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Axios on your phone

Get breaking news and scoops on the go with the Axios app.

Download for free.

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Denver news?

Get a daily digest of the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Des Moines news?

Get a daily digest of the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Twin Cities news?

Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Tampa Bay news?

Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Charlotte news?

Get a daily digest of the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sign up for Axios NW Arkansas

Stay up-to-date on the most important and interesting stories affecting NW Arkansas, authored by local reporters

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

A temperature "misery index" shows peak levels across the Southwest (orange and yellow), and the upper air flow shows how the jet stream is being pushed north, away from the heat dome parked over the Four Corners region. (Earth.nullschool.net)

A punishing and long-enduring heat wave is intensifying in parts of the West and Southwest, with heat warnings and advisories in effect across seven states Wednesday. The heat will not relent until late in the weekend.

Threat level: In the coming days, 40 million are likely to see temperatures reach or exceed 100 degrees.

Why it matters: The extreme heat is unusually intense for June, and is aggravating already dire drought conditions that could lead to another devastating wildfire season.

The details: Overnight minimum temperatures in Las Vegas barely slipped below 90°F early Wednesday, and daytime highs are anticipated to approach the city’s all-time record of 117°F today through Saturday.

  • In Phoenix, the low temperature Tuesday night into Wednesday warming was a stifling 91°F.
  • The heat wave is the result of a sprawling area of high pressure at the surface and aloft, also known as a heat dome. It's deepening the already extreme drought across the West, and adding to the significant wildfire danger across the region.
  • Wildfire risks are especially heightened from Arizona to California, northeastward into Montana. In Arizona and New Mexico, lightning from scattered thunderstorms could trigger new wildfires beginning Wednesday, as they mainly bring dry lightning and dust to a parched region.

By the numbers: In Death Valley, Calif., which holds the distinction of having recorded the hottest temperature on Earth, the June high-temperature record of 129°F is likely to be threatened Wednesday and Thursday. Death Valley hit 124°F on Tuesday.

  • The average temperature there for this time of year is about 110°F.

Several noteworthy records were tied or fell on Tuesday, including:

  • 107°F in Salt Lake City, tying the city’s all-time record for anytime of the year and beating its previous record for hottest temperature in June, which had stood at 106°F.
  • Billings, Montana also tied its all-time hottest temperature on record for any month with a high of 108°F on Tuesday.
  • Laramie, Wyo. tied its all-time high temperature record of 94°F on Tuesday.

In addition, dozens of locations in the West and Southwest set daily high temperature and record high overnight minimum temperatures on Tuesday into Wednesday, with numbers likely to total in the hundreds by this weekend.

What we're watching: The drought conditions mean there is less hydroelectric power available to handle surges in power demand across the Southwest. Lake Mead, for example, has hit its lowest levels since it was first filled in the 1930s, cutting power production at the Hoover Dam.

  • In California, temperatures are starting to increase in the Sacramento and San Joaquin River Valleys along with the foothills of the snowless Sierras, with highs around 110 degrees forecast for Thursday.
  • The National Weather Service is warning that both daytime high temperature and overnight low temperature records are likely to be broken through the weekend across inland California, and parts of the Four Corners region.
  • So far the peak of the heat has not hit the most heavily populated areas in California, which has allowed the state to avoid any rolling blackouts of the sort that occurred last year. California’s grid operator is expecting enough power supply to meet extra demand on Wednesday.
  • However, hydro power could force California officials to rely more on natural gas plants for power generation at peak times, making the state's ambitious greenhouse gas emissions reduction goals more difficult to achieve.
  • In Texas, where temperatures have been above average but not record warm, the grid operator ERCOT asked customers to conserve energy during peak hours, and reported a new June record for power demand on Tuesday.

The big picture: The West is currently experiencing its most intense and expansive drought of the 21st Century, and the heat wave and drought are reinforcing one another.

  • One of the clearest conclusions of climate science is that heat waves are becoming more intense and longer-lasting as the climate warms overall. In some cases, climate studies have shown that extreme heat events could not have occurred in the absence of human-caused global warming.
  • In recent years, there has also been a trend toward stubborn and sprawling heat domes that block storm systems and keep hot weather locked in place for days at a time.

The bottom line: The summer temperature outlook from the Weather Service shows a high likelihood of above average temperatures across the West and Southwest, in part driven by prevailing weather patterns as well as the drought conditions.

  • In other words, this heat wave is just the start of a long, sizzling and dry summer.

Go deeper

Heat wave enveloping West will shatter records, spark wildfires

The sun sets behind power lines in Rosemead, California on June 14, 2021, amid an early season heatwave across much of California this week. Photo by Frederic J. Brown/AFP via Getty Images

A dangerous and widespread mid-June heat wave is bringing blowtorch-like heat, skyrocketing power demand, and “critical” wildfire danger to much of the West Tuesday through this weekend.

Why it matters: The heat is building in a region that is experiencing a record drought, leading to dangerous fire weather conditions, straining electrical grids, and causing water supplies to dwindle further. The heat itself may prove deadly.

Grid operator asks Texans to conserve power amid outages in searing heat

Power lines stretch along along a highway near Alpine, Texas. Photo: Bill Clark/CQ-Roll Call, Inc via Getty Images

Texas' power grid operator has asked people to "reduce electric use as much as possible" until Friday following days of searing heat and a "significant number of forced generation outages."

Why it matters: The request by the Electric Reliability Council of Texas (ERCOT) comes months after a deadly winter storm blew out the state's power infrastructure and left millions of Texans without power for days.

French wine disaster points to climate change

Illustration: Shoshana Gordon/Axios

A new study finds a strong chance that climate change helped trigger the recent catastrophe that hit France's wine industry.

Driving the news: An extraordinary cold snap that gripped France in early April, just after a record-warm early spring, devastated grapes and other fruit crops.