Parts of the Western United States could see record-breaking temperatures in the coming days, the National Weather Service’s Weather Prediction Center warned, with heat advisories in place from Southern California to Yosemite and stretching east into Las Vegas.

The scorching weather is expected to be focused over inland California, Nevada, Utah and portions of Oregon and Idaho, with the worst of the heat centered over California on Friday before shifting east to Nevada and Utah on Saturday and Sunday.

On Saturday, temperatures could reach up to 106 Fahrenheit in Las Vegas, 100 in the Yosemite Valley, 100 in Boise and 93 in Salt Lake City — all close to or above the highest ever recorded in those locations on the date.

“We’re looking at extreme heat across much of the West,” said Brian Hurley, a meteorologist with the Weather Prediction Center. “There are 15 sites out West that will get close to or could break a record.”

Mr. Hurley said the warm-up would be short-lived, with temperatures dropping in California on Sunday and to the east on Monday. (He stopped short of calling it a heat wave, which is usually defined as a period of abnormally hot weather that lasts more than two days.)

It’s “a bit early” in the year for these areas to see such high temperatures, Mr. Hurley said.

The National Weather Service in Las Vegas issued an extreme heat warning for Friday and Saturday and advised people to avoid outdoor activities.