SALT LAKE CITY — Utah’s capital city has already broken its all-time hottest maximum temperature this month, reaching a blistering 109 degrees on July 13, but it just missed setting another record as the latest heat dome sets over the state.
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Salt Lake City’s official thermometer fell to 82 degrees just before 10:30 p.m. on Monday, matching the city’s highest minimum low temperature on record. The record was first set on July 13, 2021, and previously matched on July 23, 2023.
The city’s overnight low early Monday was only 84 degrees, putting it on track to break the record dating back to when the National Weather Service began tracking its weather data in 1874.
A few factors led to overnight conditions ending up abnormally warm, said Sam Webber, a meteorologist for the National Weather Service.
Salt Lake City reached a maximum high temperature of 104 degrees on Sunday, ending up just 3 degrees shy of a daily record set in 1960, which was also the previous all-time hottest temperature ever recorded. That heated the ground before clouds formed Sunday night, trapping the heat in the valley, he explained.
“That certainly helped us stay on the warmer side,” he said. “Anytime you have cloud cover overnight, it’s going to help trap a lot of that radiant heat that’s coming off the Earth, which would otherwise just radiate out into space.”
Temperatures at the official Salt Lake City site near the airport didn’t break away from 90 degrees until after 4 a.m. on Monday, with a brief dip to 84 degrees shortly before 7 a.m., as the clouds finally began to break apart. Temperatures climbed back up shortly after that, though, as the sun rose.
Monday’s high temperature ended up being 100 degrees, with a short dip to 86 degrees in the afternoon after a small storm developed. The temperature ultimately jumped between 82 and 84 during the final hour of the day, after falling to the previous record.
The tied record plays into a trend that’s emerged with urbanization, Webber said. Research has long pointed to asphalt, concrete and other development holding more daytime heat longer than a natural landscape. That, combined with hotter daytime temperatures partly from stronger high-pressure systems, has helped increase minimum temperatures.
It’s not just a Salt Lake City issue. Many parts of the world have had higher low temperatures, leading to hotter average temperatures.
Eleven out of Utah’s 13 warmest minimum temperature years have occurred since 2000, and this year’s average minimum temperature is on track to top them all, according to the National Centers for Environmental Information. Its database, tracking multiple sites across the state, dates back to 1895.
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Handling the heat
That has a human toll. The weather service issued extreme heat warnings and heat advisories this week for the Wasatch Front and northern Utah, as well as a large chunk of southern Utah.
Those warn there’s a higher risk of “little overnight relief,” compounding concerns of daytime high temperatures forecast to remain in the 100s this week. It could impact people experiencing homelessness or who are prone to heat-related illness, Webber said.
The weather service recommends that people drink plenty of fluids, stay out of the sun and remain in an air-conditioned room instead, if possible.
Salt Lake County has “cooling zones” set up for the daytime for people who don’t have access to air conditioning. Officials discussed improvements to messaging about those facilities on Monday, a spokesperson for the county told KSL.
They added that the county has also directed people experiencing homelessness to resource shelters, which also have air conditioning and can help them stay out of the heat during both the day and night.
Salt Lake City has also been working to get people experiencing homelessness to shelters or its “community corner” (702 W. 200 South), where water, snacks, and connections to other resources are available, said Amy Stock, manager of the city’s Homeless Engagement and Response Team.
State lawmakers considered a “code red” bill to help unsheltered Utahns access shelters during the heat, but it ultimately failed in 2025. It would have mirrored the winter “code blue” status, which gets people indoors when it’s considered too cold.
That would help in this situation, where resources can be limited overnight, Stock told KSL. In the meantime, she said there is still some expanded bed capacity that can help bring people indoors when it’s warm overnight.
“It is really hard, but I think there’s a sense of urgency with our resource providers and anyone who is engaging with this community to make sure what their plan is and talk through some options with them,” she added.
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