An extreme heat wave will grip the southwestern United States through early week.

A strong ridge of high pressure will take control and strengthen into this week, sending temperatures to dangerous levels.
Heat wave map
"When a ridge of high pressure like this one forms in the middle to late June, it can deliver some of the hottest weather possible to the Desert Southwest," AccuWeather Western U.S. Expert Ken Clark said.

Temperatures will run between 10 and 20 degrees Fahrenheit above average through the early part of the week.

"The peak of the heat in many areas will be on Monday, but Tuesday will be no slouch either in the high heat department," Clark said.

With multiple fires raging across the region, the heat will pose problems for firefighters.

Not only will it be hot compared to average, but temperatures will likely challenge all-time record highs.

Palm Springs, California; Phoenix, Arizona; and Las Vegas, Nevada, are just some of the many cities which will approach their all-time record-high temperatures into early week.

"This will push power consumption to the limits to keep buildings cool," AccuWeather Senior Meteorologist Matt Rinde said.

On Sunday, Phoenix topped out at 118 F, the fifth highest temperature ever recorded in the city.
Monday highs
"Outdoor activities should be severely limited if not avoided completely," Rinde said.

While the extreme heat is common during the summer months across the Southwest, the upcoming heat will be dangerous if not deadly.

"The last time temperatures were close to the levels we are expecting in the Southwest was in 2005 and 1990," Clark said.

The highest temperature on record in the United States during the month of June is 129 F in Death Valley, California, on June 30, 2013.

"That record could be in jeopardy early this week," AccuWeather Meteorologist Ryan Adamson said.

Despite very dry air and low humidity levels in place, AccuWeather RealFeel temperatures will still run a few degrees higher than the actual temperature.

Those heading outdoors for an extended period of time throughout the Southwest should wear light-colored clothing, take frequent breaks from activity and stay hydrated.

Pets should not be kept outdoors as they could develop a heat stroke or get sunburnt. Pets and children should also not be left alone in vehicles.

Those traveling at highway speeds during the peak heating in the afternoon will want to use caution as the very hot asphalt could lead to tire blowouts. The heat could also cause roadways to buckle.

"Flights could be affected at major airports, including Sky Harbor in Phoenix and McCarran in Las Vegas, as the extreme heat makes it harder for planes to get lift," Clark said.

Those hoping to beat the heat will want to head to the California beaches as temperatures will run between 30 and 40 degrees lower than most interior locations.

The strong high will begin to break down by the middle to end of the week. While it will remain hot, temperatures will dip much closer to average.