Hot and dry.
That’s a typical summer day in Utah, but without the relief of rainstorms, especially in the northern part of the state, the heat feels amplified. And it’s not all in your head. Utah summers are getting hotter.
The National Weather Service started recording Salt Lake City temperatures and weather patterns in 1874 — before Utah was a state. This month was the seventh warmest July on record, according to meteorologist Alex DeSmet, running about 3 degrees above average for this time of year.
July 2022 was the hottest on record, but DeSmet noted the data shows “every [warm July] year in the top 10 has been since 2003.”
June was even worse.
It was the second warmest June on record in Salt Lake City, up an average of 6 degrees. The hottest June on record was in 2021. DeSmet added the top five hottest June’s were all since 2015.
The 30-year average temperature for June, July and August was around 76.8 degrees, according to National Weather Service data. But within the last decade, it has increased to 79 degrees.
Both of those patterns are notable, DeSmet said, especially at night.
“It emphasizes a warming trend that we're seeing, particularly the overnight lows are a large contributor to that. The overnight lows have been trending much warmer in the Wasatch Front in particular since the 90s. And you can see that reflected in the mean temperature.”
The relentless heat is also making it harder for rain to bring relief.
Usually, rainfall brings temperatures down a few degrees. DeSmet said the hot, dry air typically brings “a ridge of high pressure” that “tends to suppress precipitation.” However, the Wasatch Front hasn’t seen a major summertime rainfall since June 21. On the other hand, southern Utah had a “wetter than normal” June, although the monsoon season has been delayed and less active.
“It's kind of been a tale of two summers, if you will. Northern Utah has been much drier than southern Utah,” DeSmet said.
What used to be anticipated summer rain “is no longer really a normal expectation,” said Jon Meyer, assistant state climatologist at the Utah Climate Center. Especially “as the region and the planet in general warms up, it becomes harder to get precipitation to occur frequently.” As a result, the monsoon season, which generally impacts southern Utah and can have lingering effects on the Wasatch Front, is now “quite a bit more variable from year to year.”
“It's really more feast or famine when it comes to the monsoon season and this year is felt a little bit more like famine than feasting like we've had two years previously,” he said. “We're also seeing less frequent precipitation on a daily timescale, so less days with precipitation occurring.”
Meyer said the rain brings cloud coverage that blocks out the scorching sun. The afternoon thunderstorms northern Utahns may have grown accustomed to brought “pretty pleasant evening conditions” that kick off “a good start for nighttime cooling thanks to pretty low humidities in the area.”
Over the last decade and a half the monsoonal patterns seemed to have changed, Meyer added. During the monsoonal months of July and August, rainfall was expected every two to three days. Now, “it seems like now we have much longer stretches where we either have all of it or we have none of it.”
As for northern Utah, rain could trickle in but DeSmet said the Climate Prediction Center is forecasting “below normal precipitation and above average temperatures at least for the next couple of weeks,” with the “odds also favoring above average temperatures and below average precipitation in August and all the way through October.”
