A heat wave is expected to blanket millions of people through the Great Basin region to the northern Plains beginning on July 12.
The National Weather Service (NWS) predicted the heatwave could set all-time high records on Sunday afternoon and peak by Tuesday with triple-digit highs.
The forecast proved correct on Sunday afternoon when Salt Lake City set an all-time record of 109 degrees Fahrenheit as of 4:58 p.m. ET.
The heat set a new all-time temperature since records began at the site in 1874.
Multiple parts of central and northern Utah will remain under an extreme heat warning until Tuesday morning.
The weather agency said temperatures could reach as high as 107 degrees Fahrenheit in the valleys of northern Utah, including the Wasatch Front and Cache Valley.
“Overnight lows in the lower to mid 70s for many valley locations will provide little in the way of overnight relief,” the NWS wrote. Records may have been broken in Montana as well.
“Unofficially, all-time record high temperatures have been broken at our 5 climate sites of Billings, Livingston, Miles City, Baker and Sheridan, WY,” NWS Billings wrote in a post on X just after 5 p.m. ET.
The last time the city reached that temperature was when it set the record in 2002.
The temperature may intensify as the day goes on, with the NWS forecasting heat could tick up to 112 degrees.
The NWS warned that the “long-duration extreme heat” would not dip much overnight to provide relief to people who don’t have cooling systems or proper hydration.
Multiple cities across Montana can expect highs over 100 degrees on Monday, Tuesday, and Wednesday as “monsoonal flow from the south will bring moisture” starting on Tuesday.
The NWS added that everyone in the heat impacted areas should stay hydrated, take frequent breaks, and limit outdoor activities if possible.
“Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke,” the agency said.
In a July 12 update, the NWS Prediction Center warned that “a significant heat wave” could occur in the Intermountain West, Northern Plains, and Upper Great Lakes, with temperatures expected to reach 95 to 105 degrees Fahrenheit through Tuesday.
The agency said the heat wave could pose a danger to those without adequate cooling or hydration.
“Extremely hot daytime highs combined with potentially record-warm lows will result in increasing heat stress over the next week due to limited relief, leading to widespread major to locally extreme heat risk,” the agency stated.
