1 of 9
Scott G Winterton, Deseret News
Anna Pawelke and other kids play in the water Monday, July 14, 2014, at the splash pad at Mountain View Park in Cottonwood Heights.
Summer at Arches can be a scorching hot place, and that is exactly what we are experiencing right now. When it is 104, you just shouldn't be hiking out there. It is brutal. —Karen Henker, supervisory ranger

SALT LAKE CITY — Monday was the hottest day of the year so far in Salt Lake City — hitting 103 degrees — and the National Weather Service is advising residents to be mindful of the heat.

Drink plenty of water. Wear loose clothing. Limit strenuous outdoor activity.

The July heat Wasatch Front residents have been dreading has hit midmonth, and there is still a lot of summer left to go.

On Sunday, Moab logged a stifling 104 degrees, prompting four heat-related medical emergencies at Arches National Park within two hours.

"Summer at Arches can be a scorching hot place, and that is exactly what we are experiencing right now," said Karen Henker, the park's supervisory ranger. "When it is 104, you just shouldn't be hiking out there. It is brutal."

About the only thing encouraging with this week's heat is that the tripe-digit temperatures are not likely to persist. Instead the Wasatch Front will hover in the low- to mid-90s into Sunday.

Larry Dunn, lead forecaster with the National Weather Service in Salt Lake City, said hitting 100 or above in July is about on target.

"The average is five a year: one in June, one in August, three in July," Dunn said. "There have been some years where we have never hit 100."

In 1993, for example, the summer slid by without hitting that wall of heat, but Salt Lake City paid for it the next year with a record-setting, relentless 21 days of triple-digit temperatures. It had only been recorded as that hot for that much of the time at Salt Lake City International Airport 33 years earlier — in 1960. Last year, Salt Lake City had 13 days that hit 100 degrees or higher.

The start of the summer swelter season means an increased emphasis by water districts to remind people of restrictions that prohibit outdoor watering between 10 a.m. and 6 p.m.

Tage Flint, general manager of the Weber Basin Water Conservancy District, said this is "crunch" time for demand on water systems.

"We have long identified the two to three weeks between July 4 and July 24 as our peak water demand time for the year. It coincides with the length of the day and also the heat," Flint said. "And all of that increase is outdoor use. Indoor use will stay fairly level throughout the year."

The reservoirs in the Weber Basin system — Rockport, East Canyon and Willard Bay — are doing OK, for now, he said.

"We filled almost none of them. They will take a hit over the next two to three weeks," Flint said.

By fall, reservoirs likely will be down 20 percent from the average and about one-quarter full, he said.

Those numbers prompted the district Monday to send out a letter to users advising that the irrigation season for both urban and agricultural customers will be shaved by two weeks, with service ending Oct. 1.

Climate change data, too, say it is likely to get worse. Scientists at the Utah Climate Center at Utah State University in Logan, for example, say trends show Utah is warming up.

"The short answer is that summers are getting warmer, and they are projected to get hotter," said Robert Davies, a physicist with the climate center.

"Ever year is not warmer than the year before, but every decade is warmer than the decade before, roughly speaking," Davies said.

A recent study by Climate Central shows that U.S. summers are warmer than in the 1970s, and by the end of this century, St. George and Las Vegas could feel like Riyadh, Saudi Arabia.

The study "1,001 Blistering Future Summers" charts daytime summer heat only. It is a projected warming trend that assumes greenhouse gas emissions will continue to increase through 2080 as they have the past several decades.

Under this scenario, Phoenix will feel Kuwait City and Boston like North Miami Beach, Florida. Closer to home, summers in Sandy and Sat Lake City will feel like Catalina Hills, Arizona, and Layton will sizzle like Tucson, Arizona.

Climate Central, a nonpartisan, nonprofit organization made up of scientists and journalists, also put together an interactive map on the data.

Twitter: amyjoi16