An early summer heat wave brought exceptional warmth to the Southwest in June 2024. On June 6 and 7, high temperatures broke calendar-day records in several communities in Nevada, Arizona, and California.
The event began with a heat dome that baked Mexico for most of May and shattered heat records there. By early June, the start of meteorological summer, the sweltering temperatures had expanded northward into the U.S. at the same time as a low-pressure blocking system set up in the Pacific Ocean.
The map above shows air temperatures across the U.S. Southwest and northern Mexico on June 6, 2024. The map was produced by combining observations from satellites and other sources with temperatures predicted by a version of the GEOS (Goddard Earth Observing System) model, which uses mathematical equations to represent physical processes in the atmosphere. The darkest reds indicate temperatures of more than 108 degrees Fahrenheit (42 degrees Celsius) at about 6.5 feet (2 meters) above the ground.
Temperatures in Las Vegas, Nevada, hit 111°F on June 6, one degree above the previous record for that date, according to the National Weather Service. That same day, temperatures soared to 112°F in Phoenix, Arizona, and 122°F in Death Valley, California. The Washington Post reported additional locations that either broke or tied temperature records that day, including Fresno, California; Amarillo, Texas; Kanab, Utah; Reno, Nevada; and Flagstaff, Arizona.
Heat waves like this one have become more frequent in the United States in recent decades, according to a team of researchers at NASA’s Goddard Space Flight Center. Using a NASA modeling system called MERRA-2 (Modern-Era Retrospective analysis for Research and Applications-2) to analyze long-term trends, the researchers found that summer heat waves in the U.S. roughly doubled in number between 1980 and 2023, increasing from an average of two to four per month.
NASA Earth Observatory image by Michala Garrison, using GEOS data from the Global Modeling and Assimilation Office at NASA GSFC. Story by Adam Voiland.
