Warmest weather since 2023 to build over Southwest into this week

After waves of cool weather by way of Pacific storms held temperatures back in March to early April, the first widespread and long-lasting surge of heat will be felt over the interior southwestern United States through early this week, AccuWeather meteorologists say.

The region, as long-term natives are aware, is known for its searing heat and relentless sunshine most days from the late spring to midautumn. However, visitors in the region may be a little surprised at how hot it can get this early in the season, and the stretch through the middle of the week will be just that.

The average date for the first 90-degree Fahrenheit high temperatures in Las Vegas is April 18, and temperatures hit that mark on Saturday and Sunday. High temperatures are forecast to remain at or above 90 degrees through Tuesday.

Interestingly, Las Vegas did not hit 80 degrees until April 10, which was about a month later than the average, on March 14. Records for Las Vegas are maintained at Harry Reid International Airport, Nevada.

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About 250 miles to the southeast, Phoenix tends to hit the 80-degree mark year-round, with the average first 90-degree day on March 30. It took almost another two weeks before the temperature reached 90 at Sky Harbor International Airport in Arizona, with a high of 94 on Apr. 11.

Temperatures in Phoenix reached the triple-digit mark on Sunday afternoon. Highs will continue to be well into the 90s through the middle of the week, with another chance of temperatures coming within a few degrees of 100 on Monday. The average date for the first triple-digit reading at Sky Harbor Airport is May 2.

Tourists take in the view at the Mather Point overlook in Grand Canyon National Park, Wednesday, Jan. 31, 2024, in Grand Canyon, Ariz. (AP Photo/Ross D. Franklin)

Clouds held temperatures back some in parts of New Mexico this past weekend. The state will likely remain to the east of the core of the heat until early in the workweek.

Abnormally dry to moderate drought conditions, even for the arid regions in Arizona and New Mexico, may allow temperatures to climb higher than they would if drought conditions were not present.

Those seeking relief from the heat and are close enough to the Pacific Ocean for a day trip will find significantly lower temperatures at the California beaches. High temperatures will generally be in the 60s, such as at Malibu Beach, California, where low morning clouds will yield to some afternoon sunshine.

Some may find relief by heading to the mountains, where the air will be cooler. The pattern will offer almost zero risk of thunderstorms over much of the region, which can spoil hiking adventures in the summertime.

California poppies bloom on a hillside on Thursday, April 13, 2023, in Golden Valley, Ariz. Super blooms typically sprout across the state after a wet winter.(AP Photo/Ty O'Neil)

There is a risk of cold-water shock, whether heading to the beaches or mountain streams and lakes for relief. The warmth will initiate or accelerate the spring thaw over the snowy high country. Streams flowing from the mountains will be running high and ice cold, so caution is advised.

Whether a resident or visitor to the area, this is a reminder to limit exposure to the sun during the midday and afternoon hours when the rays are the most intense. Experts recommend that people who plan on spending time outdoors wear sunscreen.

The interior of vehicles and pavement can become dozens of degrees hotter than the air temperature. Never leave children or pets unattended in vehicles, and avoid walking pets on paved surfaces during the daytime. Temperatures inside a vehicle can reach life-threatening levels in minutes, and the hot pavement can instantly burn paws.

Dehydration can occur even when certain individuals are perspiring very little. To reduce the risk of heat exhaustion or more serious heat stroke, experts urge regular intake of non-alcoholic and non-caffeinated fluids during hot weather, seeking shade when possible and avoiding strenuous activity during the heat of the day.

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