The hottest desert in North America is the Mojave, covering parts of California, Nevada, Utah, and Arizona. This desert environment contains the specific location responsible for the continent’s most extreme heat: Death Valley, California.
The Record Holder
The Mojave Desert holds the title of North America’s hottest place due to the temperatures documented in Death Valley National Park. At Furnace Creek, the world’s highest reliably recorded air temperature was set at 134°F (56.7°C) on July 10, 1913. Summer daily high temperatures in Death Valley frequently exceed 120°F (49°C), making it one of the most consistently hot places on Earth. Even summer nights offer little relief, with overnight lows often remaining in the 90°F to 95°F (32°C to 35°C) range.
The Unique Climate Factors Driving Extreme Heat
The extreme temperatures in Death Valley are the result of geographic and atmospheric mechanics. A primary factor is the intense rain shadow effect created by the towering Sierra Nevada mountain range to the west. Moisture-laden air moving inland from the Pacific Ocean is forced upward over these mountains, cooling and dropping its water as rain or snow before it reaches the valley. The air that eventually descends into the desert is therefore extremely dry, which prevents the cooling effect of evaporation.
The low elevation of the valley floor plays a significant role in trapping this heat; the lowest point, Badwater Basin, sits 282 feet below sea level. This deep, narrow basin is walled by steep mountain ranges, which act like a container. As the air heats up and rises, it often cools before it can escape over the peaks and sinks back down to the valley floor.
This descending air mass is subjected to atmospheric compression, a process known as adiabatic heating. As the air is forced into the lower elevation, the pressure increases, causing the air molecules to heat up dramatically. This cycle of hot air sinking, compressing, and reheating, combined with the lack of moisture, creates a superheated environment.
How the Other Major Deserts Compare
North America is home to three other major desert systems—the Sonoran, the Chihuahuan, and the Great Basin. The Great Basin Desert, located further north and at a higher average elevation, is classified as a cold desert. It experiences freezing temperatures and snow during the winter, which makes its overall climate significantly cooler than the Mojave.
The Sonoran Desert, covering much of Southern Arizona and extending into Mexico, is known for its subtropical warmth and bimodal rainfall pattern. It receives both winter rains and significant summer monsoonal moisture, which helps to mitigate the most extreme heat. Similarly, the Chihuahuan Desert, the largest in North America, also receives most of its precipitation during the summer months. Its higher average elevation and greater overall precipitation prevent the hyper-arid, heat-trapping conditions that characterize the low-lying basins of the Mojave.