History-making heat set to spread after weekend of triple-digit temperatures

A history-making heat wave that baked Southern U.S. communities with triple-digit temperatures over the weekend will offer little relief this week and could spread dangerous conditions farther across the Sun Belt.

About a third of U.S. residents were under excessive heat advisories or warnings Sunday as firefighters fought fast-moving brush fires in Southern California, temperatures neared 130 degrees Fahrenheit in Death Valley, California, and some areas — including El Paso, Texas — marked a month of 100-plus temperatures.

The center of the heat wave is expected to spread eastward Monday, with extreme temperatures continuing through at least next weekend, according to the National Weather Service. Heat indexes this week are expected to spike to dangerous levels along the more humid Gulf Coast and in the Southeast. Heat warnings were in the forecast for communities in the Pacific Northwest to the tip of Florida.