A shot of Utqiagvik on Wednesday. (University of Alaska Fairbanks)

Utqiagvik — formerly known as Barrow — in Alaska is among the fastest-warming cities in the nation thanks to human-induced climate change. But Wednesday, the city located on the state’s North Slope set its first record-low temperature in 13 years.

The United States’ northernmost city plummeted to a bone-chilling minus-20 degrees Wednesday, beating out the previous daily record set in 1973. Not only is that its first record low in more than a decade, but it’s also the latest in the season that Utqiagvik has observed a temperature so frigid.

Before Wednesday, the last time Utqiagvik saw a record low was Dec. 21, 2007, when the mercury fell to minus-42 degrees. Since then, Utqiagvik had not set or tied a record low until this week — though the city has managed to snag a whopping 112 record-high temperatures during that time period.

Wednesday’s cold was related to part of the polar vortex, which helps govern the distribution of ultracold air during the winter months.

“We had a deep low aloft that was pretty much over the North Pole,” said Jim Brader, a meteorologist at the National Weather Service office in Fairbanks, Alaska. “One lobe of [the polar vortex] moved across the Barrow area [on Wednesday], and then we had clearing skies. As the skies cleared, the temperature dropped 20 degrees.”

While temperatures of minus-20 and below are quite common in Utqiagvik, it’s unusual to see air so cold this late in the season. By late April, Utqiagvik sees more than 19 hours of sunlight each day, with the sun never setting between May 11 and Aug. 2. That lack of darkness can make it tough to take full advantage of radiational cooling, which helps temperatures plummet on clear and calm nights, in particular.

However, a perfect combination of northerly winds, nearby sea ice and a stout snowpack worked together to push Utqiagvik’s Wednesday low temperature down into record territory.

Brader said storms that swept through the Bering Sea three weeks ago churned up the sea ice cover, and northerly winds since then have pushed the ice front well south of Utqiagvik.

This has helped to maintain enough ice cover around the northern outpost to allow for such cold conditions to occur.

Much of this ice, however, is young and fragmented. As the ice is broken into smaller pieces by melting and the mechanics of strong early spring storm systems, it becomes more mobile.

“This is a good example of how, even in a warming world, it can still get cold,” said Rick Thoman, an Alaska climate specialist at the Alaska Center for Climate Assessment and Policy.

“This is the time of year on the North Slope, around the end of April, when you can get … all of the meteorology to work out. The sea ice so far is pretty solid, you have good snow cover, a cold-enough air mass, [and an] offshore breeze.”

Sea ice is perhaps the greatest influencer of the weather in Utqiagvik; the hasty retreat of sea ice and the emergence of exposed ocean waters in recent years have amplified Utqiagvik’s climate-driven warming rate even more.

So while Wednesday’s morning low did beat out a previous record by a mere degree, it’s negligible in the face of 112 record high temperatures tied or broken in the time since Utqiagvik’s last record low.

“In baseball, you don’t see 112 to 1,” Thoman said. “That’s a blowout.”

Utqiagvik is ground zero for climate change in the United States, with the city rapidly warming more than five degrees in the past century. That warming has accelerated to an extreme rate in the past five years. Before 2016, the community had only seen one year with an average temperature above 16 degrees; since then, Utqiagvik has exceeded that threshold every year.

In 2019, Utqiagvik’s average temperature was 20.8 degrees; and four out of the five warmest years on record for Utqiagvik have occurred in the past five years. The exceptional rate of warming is largely driven by a loss of nearby sea ice in the Chukchi and Beaufort seas, which is itself tied to climate change.

“The really big difference in [Utqiagvik] is the longer open-water season,” Brader said. “The Chukchi Sea has been melting much farther north. There’s just a big reservoir of water and heat [where there used to be ice]. If you have any wind blowing across that, it’s going to push the warm air into [Utqiagvik]. The lengthened season of open water has made the big difference there.”

Brader said he arrived in the area about 30 years ago and has noticed significant changes in the climate during the course of his career.

Thoman said that it’s tricky to predict exactly how Utqiagvik’s specific warming trend will evolve in the years ahead but that the upward spike in temperatures is unlikely to quit.

“The escalator’s going in only one direction,” he warned.