19 cities have broken their all-time high in this heat wave. Again, not the calendar day high, but all-time on record. This include Salt Lake City, Phoenix, and Las Vegas, which while in the same part of the country, aren't right next to each other either.
And this is another event of duration.
article said:
Las Vegas broke another record on Wednesday when it experienced its fifth straight day of temperatures of 115 degrees or higher. Prior to this week, Las Vegas had never experienced a temperature that exceeded 117 degrees, but the temperature there has reached or surpassed the 117 mark three times this week alone.
Sin City could also break its record of 10 consecutive days of 110-degree temperatures or higher by the end of this week. The temperature in Las Vegas is forecast to climb to a blistering 118 degrees on Thursday, 115 on Friday, and 112 on Saturday, according to the National Weather Service.
So while some portions of Southern California are pleasant, much more of the Southwest is being torched to levels not seen in 150 years.