Phoenix suffers a record 31 straight days of 110-degree highs, and more heat is on the way
- On Monday, the high temperature in Phoenix was 108 degrees Fahrenheit, ending the 31-day record of consecutive days of high temperatures of 110 degrees Fahrenheit or higher.
- More hot weather is on the way for Phoenix. “Wednesday will mark the start of a warming trend with high temperatures eventually expected to once again top 110 degrees over much of the lower deserts by Friday,” the National Weather Service said.
- In July, Phoenix set a record for the highest monthly average temperature of any U.S. city, at 102.7 degrees Fahrenheit.
On Monday, Phoenix finally stopped adding new notches to its record of consecutive days with temperatures of 110 degrees Fahrenheit or higher, but more hot days are just around the corner.
The high temperature at Phoenix Sky Harbor Airport reached 108 degrees Monday, according to a social media post from the National Weather Service in Phoenix.
That high on Monday ended the 31-day record of consecutive days of high temperatures of 110 degrees Fahrenheit or higher.
The 31-day streak blew past the previous record of 18 consecutive days set in 1974, according to the weather service.
While the reprieve was desperately welcome, temperatures are due to start climbing again Wednesday, the weather service said in its Tuesday bulletin.
“Wednesday will mark the start of a warming trend with high temperatures eventually expected to once again top 110 degrees over much of the lower deserts by Friday. An Excessive Heat Watch has been issued for much of south-central Arizona from Friday through Sunday,” the weather service said.
Phoenix is accustomed to hot weather in the summer, but global warming trends have added heat, according to research from scientists at the World Weather Attribution, an organization that quantifies how much of an extreme weather event is attributable to climate change.
The organization’s scientists “found that the Southwest heat wave in July was almost 4 degrees Fahrenheit warmer as a result of climate change,” Erinanne M. Saffell, Arizona’s state climatologist and director of the Arizona State Climate Office, told CNBC.
The heat in Phoenix was also a result of a stubborn weather pattern called a “heat dome,” lack of rain, and what Saffell called “an extreme heat island,” where buildings, roads and the infrastructure of urban areas contribute to higher temperatures than more rural areas.
“The Phoenix urban heat island has twice the signature of the global impact. The urban heat island largely keeps night temperatures warmer,” Saffell told CNBC. “In July, night temperatures did not cool off below 90 degrees Fahrenheit on 19 days and set a new record ‘max’ minimum temperature of 97 degrees Fahrenheit. That means it didn’t cool off below 97 degrees Fahrenheit that night.”
The brutal month made July in Phoenix the hottest month on record for any U.S. city, with an average temperature of 102.7 degrees, according to data posted on a social media account of the Arizona State Climatologist and Arizona State Climate Office.
The previous average monthly high for Phoenix was 99.1 degrees, in August 2020, and the previous national high was set in Lake Havasu City, Arizona, in July 1996, when it experienced an average temperature of 102.2 degrees, Saffell told CNBC.
Prolonged periods of extreme heat are dangerous. According to the most recent heat mortality report from Maricopa County, where Phoenix is located, 25 deaths from the heat have been confirmed. Another 249 deaths are still under investigation to determine if they are attributable to heat.
“The heat has been unrelenting in our community. I am so thankful to our first responders who are out there taking care of people who are vulnerable, to anyone who has to work outdoors,” Phoenix Mayor Kate Gallego told CBS’ Margaret Brennon on “Face the Nation” on July 23.
Phoenix has mobile cooling units that it dispatches to emergency zones, and can give people IVs that have been cooled, in order to lower their temperature from the inside, Gallego said.