Dean Leano takes a water break while photographing tourists at the Welcome to Fabulous Las Vegas sign in Las Vegas on Thursday. Las Vegas Sun via AP

RENO — The first heat wave of the year maintained its grip on the U.S. Southwest on Friday, a day after records tumbled across the region as temperatures soared past 110 degrees Fahrenheit from California to Arizona.

Although the official start of summer is still two weeks away, roughly half of Arizona and Nevada were under an excessive heat alert, which the National Weather Service extended until Friday evening. The alert was extended through Saturday in Las Vegas, where it’s never been hotter this early in the year.

Temperatures were expected to slowly retreat over the weekend, but will remain above normal into early next week.

After setting a new record of 111 F on Thursday — which also equaled the earliest time of year the high reached at least 110 F — Las Vegas quickly broke another record early Friday afternoon as it hit 110 F and surpassed the record high for the day set in 2013. And the National Weather Service office there said it could still get hotter before sundown.

In Phoenix, the new record high of 113 F on Thursday leapfrogged the old mark of 111 F set in 2016. Forecasters called the conditions “dangerously hot.”

“It’s so hot,” said 9-year-old Eleanor Wallace, who was visiting Phoenix from northern Utah on Thursday on a hike to celebrate her birthday with her mother, Megan Wallace.

There were no immediate reports of any heat-related deaths or serious injuries.

The National Weather Service expects mild cooling regionwide this weekend, but only by a few degrees. In central and southern Arizona and parts of southern Nevada, that will still mean triple-digit highs, even up to 110 F.

Several other areas of Arizona, California and Nevada also broke records Thursday by a degree or two, including Death Valley National Park with a record high for the date of 122 F, topping the 121 F dating to 1996 in the desert that sits 194 feet below sea level near the California-Nevada line. Records there date to 1911.