Andy LarsenThis week’s forecast from the National Weather Service is clear:
“To put it mildly, widespread record-breaking temperatures are pretty much a certainty, and many records will be broken by impressive, if not historic margins,” Seth Warthen, lead meteorologist in the Salt Lake City office, wrote.
Warthen may have put it “mildly” — but this week’s weather will be anything but mild.
Starting in the middle of this week, a high-pressure system will move across the western United States. For some states, like Arizona, that means temperatures as high as 100 degrees.
For us in Utah, it means highs in the upper 70s or lower 80s in the north and highs in the upper 90s in St. George — temperatures 20 or 30 degrees above what would be considered normal.
The high-powered models meteorologists use to project the weather tend to say that the heat could decline somewhat around Sunday or Monday — but still without moisture in sight until the end of next week.
Historical heat
(Bethany Baker | The Salt Lake Tribune) The sun sets over Salt Lake City, seen from the Twin Peaks trail on Friday, July 25, 2025. Forecasters expect record-setting high temperatures this week in Utah.
There is one stat that probably sums up this heat wave the simplest: At the weather station at Salt Lake City International Airport, we likely will see 80 degrees on thermometers at the earliest point in the year by far. The earliest 80-degree day currently on record was on March 31, 2012, and we likely will beat that by 11 days. On average, highs of 80 degrees don’t occur until June.
But we can also break down just how unusual these forecasted temperatures are day by day. Thanks to the Iowa Environmental Mesonet’s easy-to-use database of weather measurements from stations all over the world, we can chart the high temperature at Salt Lake City International Airport for the last 75 years and change.
Temperatures will get quite high on Tuesday, approaching 70 in Salt Lake City, but get into record-setting territory at the end of the week. And they are not records being set by small amounts, either: They are five or six degrees higher than we’ve ever seen on those days before.
The explanation
So what’s going on here? I called Monica Traphagan, another senior meteorologist at the National Weather Service’s office in Salt Lake City.
“We’ve got a big, strong ridge off the Pacific Coast that’s going to be slowly moving east over the next several days. It’s much stronger than what we typically see in spring,” she said. “This is more like a summertime ridge with the strength of it, and as a result, we’re having this persistent high-pressure system. Now that we’re in the part of the season where that wouldn’t cause an inversion, it just means the temperatures are going to be unseasonably warm.”
Traphagan also noted that this was the continuation of what was already the warmest winter in Salt Lake City on record — the storms we did have tended to be “atmospheric river-type storms” coming from tropical flows from the southwest rather than the colder Pacific Northwest regions.
But, Traphagan noted, the long-range forecasts continue to show unseasonably warm weather and relatively low precipitation are “more likely than not, particularly for southern Utah.”
Andy Larsen is a data columnist for The Salt Lake Tribune. You can reach him at alarsen@sltrib.com.
Andy Larsen, a lifelong Utah resident who graduated with a math degree from Salt Lake City's Westminster College, is now The Tribune’s data columnist (after previously covering the Utah Jazz). When he's not writing about numbers in our world, Andy enjoys playing soccer, tennis and chess.