Much of the United States has been extremely hot this July, and that includes the Grand Canyon. An excessive heat warning issued by the National Weather Service (NWS) for Saturday, July 23, applies to those parts of the canyon at elevations below 4,000 feet. Daytime temperatures in the canyon at that elevation could climb to between 110 and 115 degrees Fahrenheit, with nighttime temperatures dropping to 74 to 84 degrees.
The NWS attributes these extreme temperatures to a high-pressure system that has settled over the region. Other sites in the region also affected by the heat warning include the parts of Phantom Ranch, Supai, Cottonwood, Camp Verde, Cordes Junction, and Bagdad below 4,000 feet. By contrast, the Flagstaff area is expected to have relatively low and safe temperatures on July 23, with a high of 87 degrees.
Excessive heat can be very dangerous—and potentially fatal—for anyone spending a significant amount of time outdoors, but especially for people doing strenuous activities and people with health problems. It is also dangerous for people indoors without air conditioning. In addition, pets and other animals are just as at risk of heat-related problems as people.
Public health experts strongly recommend that, during excessive heat waves, people and animals stay out of the sun and in air-conditioned rooms as much as possible. And they should drink plenty of water or other non-alcoholic fluids. People who must spend a lot of time outdoors can protect themselves from heat-related problems by wearing light-colored, loose-fitting clothing, drinking a lot of water, and taking frequent breaks out of the sun.
If a person begins to experience heat stroke or heat exhaustion, 911 should be called immediately.