Temperatures are expected to reach 106 degrees Fahrenheit in the Dallas-Fort Worth area, and cities further west may see temperatures of 120 degrees.
This intense heat can become deadly, and local authorities urge people to take the risk seriously.
In the southwest, the heat is expected to reach near record levels. Tuscon, Arizona, can expect a high of 113 degrees on Sunday, and Phoenix can hit 116. Las Vegas is forecast to hit 110, and Death Valley will see a high of 116 this weekend.
A heat ad covers most of Texas, virtually all of Louisiana, and large swaths of Mississippi, Alabama, Oklahoma, and New Mexico. Albuquerque is expected to hit 101 degrees on Saturday, and Oklahoma City is forecast to hit 106 degrees.
In the southeast, temperatures will remain in the mid-1990s but humidity will cause heat rates to soar. Jackson, Mississippi, will see a heat index of 109, New Orleans will reach 110, and Mobile, Alabama, will approach a heat index of 114.
Monthly heat records are unlikely to be broken in the region this weekend. But temperatures remain high for the time of year, and its duration is remarkable.
Heat waves, particularly in the southwest, often bring relief with cooler temperatures at night, but that effect is limited this weekend.
The high temperatures coincide with other unusual weather throughout the country. Tropical storm Fay is affecting the mid-Atlantic, and parts of the Pacific Northwest are experiencing below-average temperatures in July.
Heat warnings are different across the country.
In the southwest, “we use what we call a heat hazard,” said Marvin Percha, a meteorologist with the National Weather Service. This assessment takes weather patterns and judges them against what is normal for the area. The rarity of an event guides its level of risk.
This is different from other areas of the country, where heat rates are most important in heat warnings. A heat advisory, such as the one covering the southeast, uses heat indices combined with the actual temperature rather than the temperature standards for the area.
While counseling systems differ regionally, the message is the same: The expected high heat in much of the south this weekend is dangerous, and residents must be prepared to take steps to be safe.
Staying cool during COVID-19
“If you have to be outside, try to limit your exposure and stay well hydrated,” Percha said. “Find air-conditioned cooling centers if necessary.”