Extreme Heat Wave Coming for Southwest: Arizona, New Mexico, California

A man walks along a street as temperatures rise above 100 degrees Fahrenheit, in Yuba City, Calif., on June 30, 2023. Carlos Barria/Reuters

Forecasters are warning of a long and intense heat wave coming for the U.S. Southwest that could rank among the most severe in recent history.

The focal point of the blistering heat will fall mostly in Arizona, California, and New Mexico, with peak intensity expected later in the week, according to regional offices of the National Weather Service (NWS).

The forecasts came at the tail end of a week that hit an average global record high temperature, according to the University of Maine’s Climate Reanalyzer project.

Construction worker Fernando Padilla wipes his face as he works in the heat, in Nashville, Tenn., on June 30, 2023. George Walker IV/AP Photo

Arizona

In Phoenix, there have been eight consecutive 110-plus-degree days amid a growing likelihood of temperatures breaking records.

Even though models updated on July 8 are showing slightly cooler temperatures for next week than previous projections did, the current heat wave will probably continue as the high pressure system strengthens into next week, NWS Phoenix said in its latest forecast discussion.

“The atmospheric set up for the latter half of next week also looks to have similarities to the conditions on July 28, 1995 that led to Phoenix reaching 121 degrees and Yuma hit 124 degrees,” NWS Phoenix said in an earlier July 7 weather discussion note.

A lone motorcycle rider travels on historic Route 66 across the western Arizona desert on the approach to Oatman, Ariz., on July 12, 2003. Robyn Beck/AFP/Getty Images

“Even if we do not get quite that hot during this current heat wave, this should go down as one of the longest, if not the longest duration heat wave this area has ever seen,” it added.

Excessive heat warnings are currently in effect across south-central Arizona through at least July 16, with an excessive heat watch going into effect on Tuesday and lasting until Sunday as well.

“By next weekend, there is a greater chance for even hotter temperatures,” NWS Phoenix said, which will likely cause a further extension of various excessive heat products such as warnings and watches.

“Very hot temperatures will continue through all of next week with the worst of the heat starting the middle of next week. Make sure to practice heat safety when heading outdoors,” NWS Phoenix said in a statement on Twitter.

California

In California, cooler temperatures in the immediate term will give way to a heat wave next week, NWS Los Angeles said in its latest forecast discussion.

“Forecast-wise for the immediate short term, no major issues are anticipated,” the agency said.

However, forecasters expect that a warming trend will become more significant as the week progresses next week, with the hottest temperatures expected away from coastal areas.

“A significant warming trend is forecast for next week as strong high pressure aloft builds in over the region. A prolonged period of heat is likely away from the coast through the week,” NWS Los Angeles County said in the discussion note.

The San Antonio Fire spreads uphill west of Petaluma, Calif., on June 30, 2023. Kent Porter/The Press Democrat via AP

Excessive heat watches are in effect for the interior Los Angeles County area between Tuesday and Friday of next week, with forecasters expecting that they'll need to be extended, as data points to hotter temperatures toward the end of next week.

In the Bay Area, there are several “hot spots” such as Pinnacles and Parkfield reaching the low 100s, though with most interior locations reaching the mid-90s on Saturday, according to NWS San Francisco.

“Increasing potential for above average temperatures next week,” NWS Bay Area said in a recent tweet. “In fact, some inland areas may get downright hot!”

New Mexico

New Mexico is bracing for scorching temperatures across much of the state, coupled with a high risk of strong to severe thunderstorms across northeast and east central areas through Monday.

“Very hot temperatures will continue for the next seven days near record high temperatures in an increasing number of locations during the coming work week,” NWS Albuquerque said in a discussion note.

Warm to hot temperatures are forecast for Saturday in New Mexico, with severe thunderstorms in the eastern parts of the state along with the possibility of heavy downpours, large hail, and damaging winds.

It comes as the Earth’s average temperature set a new unofficial record high on Thursday in a week that has been rated as the hottest on record, according to data compiled by the University of Maine’s Climate Reanalyzer project.

Thursday’s planetary average exceeded the 62.9-degree mark set Tuesday and matched on Wednesday.

“It is certainly plausible that the past couple days and past week were the warmest days globally in 120,000 years,” University of Pennsylvania scientist Michael Mann told The Associated Press.

High land temperatures have generally been matched by those on the sea, with warming intensified by an El Nino event, a natural cycle that adds more heat to the Earth’s system.

Warmer seas could also mean less wind and rain, leading to even more heat on land, some scientists say.

In order to cope with higher temperatures, NWS recommends drinking plenty of water, wearing light clothing, finding air conditioned places, avoiding strenuous activities, never leaving people or pets in cars, and watching for heat cramps, exhaustion, and stroke.