Climate Signals Summary: Climate change is increasing the frequency, intensity, and length of heat waves. In the southwestern US, around 80 percent of monthly hot temperature records were due to climate change.
Article Excerpt: Sweltering heat has roasted residents throughout the Southwest and rewritten a few records in the process. As social distancing mandates have forced people to stay at home and away from beaches or parks, citizens in cities such as Las Vegas and Phoenix are in search of new ways to cool off.
On Wednesday, Las Vegas locals saw the mercury in thermometers nearly surpass the triple-digit barrier for the first time ever in April. While temperatures topped out at 99 degrees Fahrenheit at McCarren International Airport, the heat blast still matched the city's April record high.
At 18 degrees higher than the historical average, Wednesday’s temperatures would have sent most Phoenicians scurrying for the local swimming pool or park in any other year.
In the Southwest, Las Vegas wasn't the only city to sweat through the first half of the week. Phoenix joined the triple-digit heat club with a string of stifling days.
"Phoenix recorded its first 100-degree day of the year on Sunday and, for good measure, tacked on four more through Thursday, with highs still expected to eclipse 100 on Friday," AccuWeather Senior Meteorologist Bill Deger said. "The April record of 105 in Phoenix was nearly toppled on Wednesday, when it reached 104 at Sky Harbor Airport."
The five straight days of 100 degree heat from April 26-30 became the third longest streak in April since records began in Phoenix in 1896.
Phoenix’s high of 104 F on Wednesday was 15 degrees above normal and the heat didn’t let up overnight. On Thursday morning, a new record max low temperature was set in Phoenix when the temperature refused to budge below 75 F.
In Los Angeles, temperatures peaked at 93 F last week and have remained at least 5 degrees above historical average this week. Farther inland, Death Valley peaked at 112 F on Wednesday. Considered the hottest place in the U.S., the Wednesday mark was just one degree shy of its April record.