The fall air hasn’t been as crisp this year.
Utah just had its warmest November on record. The average temperature was more than one degree higher than the state’s previous record set in 2017, according to data from the National Oceanic and Atmospheric Administration.
Utah also broke the record for its warmest autumn (meteorological fall runs from September through November). While fall warmth may not be as obvious as summer heat waves, it’s another local example of how climate change, driven by fossil fuel emissions, is shifting global weather.
“It’s not surprising or shocking to see record warmth,” said Dan McEvoy, a climatologist at the Western Regional Climate Center. “Just the spatial extent of the warmth in November was impressive. It wasn’t isolated to one state or one part of the West.”
Neighbors Idaho and Nevada had their warmest November, too. Those two states, along with New Mexico, Oregon and Washington, all joined Utah in setting records for the fall.
“There's no disputing the data,” McEvoy said. “It's been extremely warm for most of the fall for a lot of the West.”
The warm autumn has also put Salt Lake City on track for its second-warmest year on record. Based on average temperatures from January through November, it’s running 3.3 degrees warmer than its average from 1991-2020. That’s one of the highest increases of any major city in the U.S.
The warm conditions have had a big impact on this season’s lack of snowpack, McEvoy said. One reason is that precipitation has fallen as rain instead of the white stuff. Another is that the low-pressure systems that brought much of the Southwest’s moisture in November were cut off from the jet stream, he said, and kept cold air pushed off to the north.
There’s still time to turn things around, but it puts Utah’s future water supply — 95% of which comes from snowpack — in a precarious spot.
“The only aspect of predictability is that it's just going to be a little harder for regions that fell behind in the snowpack to catch up throughout the winter,” he said. “That would require above-average snowfall to make up some of those deficits.”
The warm fall has also shown up on Utah’s mountain roads.
State Route 148, which leads to the south entrance to Cedar Breaks National Monument in southwest Utah, typically closes for the winter by mid-November, but nearly a month later, it remains open.
It’s the same story for Mirror Lake Highway and Wolf Creek Highway in the Uinta Mountains, said Cody Oppermann, a meteorologist with the Utah Department of Transportation. The two scenic byways often close in October or November, but are still open.
“In short, the answer is yes,” Oppermann said. “A lot of these routes are usually closed earlier than they have been.”
Some other seasonal highways that have already closed for the year did so later than normal, he said.
For farmers, warmer falls offer a mixed bag, said Reagan Wytsalucy, an associate professor with Utah State University extension in San Juan County.
The upside is that it can help some crops, such as winter wheat, get established before the first frost and be more durable heading into the winter.
“If these are consistent climate conditions moving forward, then we can adjust our growing season,” Wytsalucy said. “It can open up more opportunities to grow a variety of different types of species that would be tolerant of the warmer climate conditions.”
But switching to new and different crops is a big individual and systemic lift. And, she pointed out, there’s still always the risk of a stray cold snap killing things.
Warmer falls also come with potentially destructive downsides. A delayed winter may lead to pest problems the next spring, she said, because it extends the life cycle of insects. Warmer soils may give noxious weeds a leg up, too.
The biggest concern, Wytsalucy said, is that higher temperatures tend to accelerate evaporation and dry out soils, which can cause crop failure and increase erosion in bare fields.
“Our key advantage right now that we're seeing — despite the warmer conditions — is that we've had some pretty good moisture. I think that kind of helps balance things out,” she said.
Utah will need more of that moisture in the days to come.
The latest forecasts from the National Oceanic and Atmospheric Administration point to above-average temperatures across the state for at least the next two weeks.
