Triple-digit temperatures persist across Southwest as heat dome expands

Denise Chow
Updated

Severe heat continues to build in Arizona and across the Southwest, with conditions in Phoenix threatening to become the city’s longest heat wave on record, according to the National Weather Service.

High temperatures in Phoenix have been in the triple digits every day for nearly a month. A persistent heat dome over the Southwest is bringing “anomalously hot summer weather” to the region, the weather service said Tuesday in its short-range forecast.

Now, the city is poised to tie or break the record for most consecutive days at or above 110 degrees Fahrenheit. The current record of 18 days has stood for almost five decades. As of Monday, Phoenix’s streak stands at 11 days, making it currently the fourth-longest heat wave on record, according to the Phoenix office of the NWS.

A hiker at Piestawa Peak during a heatwave in Phoenix on July 11, 2023. (Ash Ponders / Bloomberg via Getty Images)
A hiker at Piestawa Peak during a heatwave in Phoenix on July 11, 2023. (Ash Ponders / Bloomberg via Getty Images)

The long-lived heat wave in the Southwest comes on the heels of a hot June that included several weeks of dangerously hot temperatures and humidity in Texas and across the South.

Climate change is expected to make bouts of unrelenting heat more common in the future. Studies have shown that global warming is increasing the frequency, intensity and duration of extreme heat events.

Forecasts show that the ongoing heat wave will continue to scorch the Southwest this week and into next week, and will expand across the southern portion of the United States.

“Numerous heat-related advisories/watches/warnings are in effect from Florida to Texas to California,” the weather service said Tuesday.

Dangerously hot conditions are projected to envelop much of Nevada later in the week and into the weekend.

“We don’t want to sound like a broken record, but it’s important you know that dangerous heat is coming!” officials with the Las Vegas office of the NWS tweeted Tuesday. “Temperatures later this week may challenge daily and all-time records, with little-to-no overnight relief. Major to Extreme HeatRisk is anticipated!”

Temperatures in Las Vegas may hit 116 F several times over the next week. Forecast temperatures at Death Valley National Park, which straddles Nevada and California, could spike to nearly 130 F over the weekend, according to the National Weather Service.

Image: Salvation Army volunteer Soila Arias gives water to a man at their Valley Heat Relief Station on July 11, 2023 in Phoenix. (Matt York / AP)
Image: Salvation Army volunteer Soila Arias gives water to a man at their Valley Heat Relief Station on July 11, 2023 in Phoenix. (Matt York / AP)

In some parts of Florida, heat index values, which represent how conditions feel when humidity and air temperatures are combined, will range between 105 and 110 F. High heat and humidity is also expected to spread from eastern Texas up into the southern and central Plains by midweek.

Widespread excessive heat watches will take effect across California later this week, as temperatures are projected to spike into the high 90s and into the triple digits in places.

Advertisement