Heat wave bakes U.S. Southwest, temperatures rise well above 100 degrees

A scorching heat wave was expected to blanket the U.S. Southwest beginning on Wednesday and push temperatures over 100 degrees F for the rest of week, leading forecasters to warn residents to stay indoors and avoid strenuous activities.

Afternoon temperatures are forecast to soar well above 100 degrees Fahrenheit (38 C) across southern Texas, Arizona and up through Central California and into Western Nevada until Sunday evening, the National Weather Service (NWS) said in several advisories.

On Wednesday morning, it had already reached 100 degrees in Phoenix and was expected to reach 107 in Las Vegas by the afternoon. It was 106 in both Furnace Creek and Stovepipe Wells in Death Valley, California at noon.

"It is not terribly unusual to see this in early to mid June," said Morgan Stessman, a NWS meteorologist based in Las Vegas. "If you are thinking about doing outdoor activities, it's usually best to try to do them early morning or later in the evening."

The weather service said extreme heat will significantly increase the potential for heat-related illnesses, particularly for people working or participating in outdoor activities and those consuming alcohol.

Health officials in the Las Vegas and Phoenix metro areas opened cooling stations in anticipation of the hot weather.

"Stay hydrated and NEVER leave children and pets unattended in vehicles," Clark County, Nevada, home to Las Vegas, said in a tweet.