In June 2024, early summer heat waves hit both the western and eastern United States. Temperatures in July have not brought much relief.
The map above shows air temperatures across the U.S. on July 10, 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 104 degrees Fahrenheit (40 degrees Celsius) at about 6.5 feet (2 meters) above the ground.
In the West, areas of intense heat are visible across many areas west of the Rockies, from Mexico to Canada. According to the National Weather Service (NWS), temperatures commonly surged over 100°F on July 10, causing widespread heat risk. On that same day, parts of the East—from South Carolina to Massachusetts—were under heat warnings or advisories. High humidity boosted the heat index to over 100°F in some places. The higher the heat index, which indicates how hot it feels when accounting for both temperature and relative humidity, the harder it is for the human body to cool itself.
In parts of the Midwest, cooler-than-average temperatures followed the northeastward path of Cyclone Beryl’s remnants. But in southeast Texas, temperatures on July 10 remained in the 90s, and heat indices climbed over 100°F. After Beryl swept ashore as a Category 1 hurricane on July 8, the lack of electrical power and air conditioning raised the risk for heat-related illnesses, according to NWS Houston.
The second map shows a detailed view of the Southwest, where heat in early July has been especially intense. On July 10, Las Vegas saw its fifth consecutive day of temperatures of at least 115°F (46°C), according to NWS Las Vegas. Those temperatures hovered around the city’s previous all-time high of 117°F (47°C) but below the new all-time record of 120°F (49°C) measured on July 7, 2024. Palm Springs, California, also hit an all-time high of 124°F on July 5, and Death Valley approached its record high when the temperature reached 129°F on July 7, according to The Washington Post.
Forecasters expect little relief from the long-lasting heat wave in the coming days, with dangerous temperatures in the West persisting through July 13 and the threat of extreme heat in the West increasing starting July 15.
NASA Earth Observatory images by Wanmei Liang, using GEOS-5 data from the Global Modeling and Assimilation Office at NASA GSFC. Story by Kathryn Hansen.
