Average temperatures over a 45-day period between late December and early February in Alaska. (WeatherBell)

Mere months after obliterating records amid its warmest year ever documented, Alaska is coping with exceptional conditions yet again — but this time for abnormally cold conditions. The Last Frontier has recently endured some of its coldest weather in eight years, with temperatures crashing as low as minus-60 in some spots.

Other than two or three mild days this week, the cold has been bitter and relentless. And the harsh, biting chill will return this weekend.

Sea ice and snow packs are expanding, and Alaskans are experiencing the kind of winter the state is known for.

But, while notable, the intensity of the cold is tamer than it was several decades ago, which experts link to climate change.

The cold, by the numbers


Toksook Bay, Alaska, in December. (Matt Hage/AP Images for U.S. Census Bureau)

In Bettles, Alaska, 29 nights have dropped below minus-30 degrees since Christmas. Twenty of those have fallen below minus-40, nine below minus-50 and one as low as minus-60.

In Utqiagvik, Alaska’s northernmost city (formerly known as Barrow), the high temperature didn’t exceed minus-16 between Jan. 24 and Feb. 17. Even after a brief warm-up, the city has yet to crack zero.

Fairbanks, a city of roughly 32,000, has seen a week’s worth of minus-30 degree nights so far this February.

But despite the widespread and persistent chill, not a single daily minimum temperature record has fallen this year in any of the three cities.

“It’s been a duration issue rather than about exceptionally low temperatures,” said Rick Thoman, an Alaska climate specialist at the University of Alaska at Fairbanks.

“There have been only a very few daily records. In fact, so far in 2020, just looking at the major long-term climate sites, only three record lows have been set … and two record highs.”

The cold’s persistence, however, has been notable. Thomas says the 25 consecutive days below minus-15 in Utqiagvik was “the second-longest stretch there.”

“But the average high temperatures didn’t even make [a] top 10 [record],” Thoman explained. “There was nothing close to [a] record.”

A welcome return to cold

The cold has been welcomed by many in Alaska, a state whose economy and way of life have been built upon once-dependable winter freezes and formerly reliable ocean ice cover.

“It’s very good news as far as it goes,” Thoman said. “We’ve had indisputably the coldest winter in a number of years over mainland Alaska. The [sea] ice is in a much better place than it was. It’s almost exactly at the long-term normal. We’re at nearly 100 percent of average ice cover.”

The winter is shaping up to be the coldest since 2011-2012.

Things are also looking up for snow-starved areas around Anchorage, the state’s largest city, which in recent years have lacked their typical accumulations.

“Places that have been frequently hurting for snow, like the mountains around Anchorage … have got decent snow this winter,” Thoman said. “Same in southeast Alaska. Low-elevation snow is running around normal, and at the higher elevations, they’ve got a good snow pack.”

Thoman explained that the high-elevation snow will be especially beneficial once it melts in the springtime. That’s because much of southeast Alaska relies on snowmelt to generate electricity at hydropower dams.

“Even though temperatures have not been wildly cold, at elevation there’s been copious snow,” Thoman said.

The polar vortex’s role


Winds (in barbs) and height of various air pressure levels (contours/colors) of the stratospheric polar vortex. (Hannah E. Attard)

The cold settled into most areas during the penultimate week in December. “It was quite a dramatic temperature change,” Thoman said.

Much of the stubborn cold relates to the polar vortex, which, as of late, has been nearing record strength in the upper atmosphere. That doughnut of swirling winds and extreme cold has largely evaded the Lower 48, banked far to the north. That’s left most of the mid-latitudes anomalously warm, having escaped the vortex’s icy throes.

But Alaska has been in the crosshairs of the polar vortex’s local influence at the surface, featuring relentless cold with little interruption.

“It’s been a very stable pattern,” Thoman said. “Practically all of Eurasia has been hot at high latitudes. It’s more that the pattern has been so [constant and unwavering], and Alaska has just happened to be in that lobe of cold.”

Temperatures over the next week and a half will average some 15 to 25 degrees below average for most of Alaska.

The cold follows a year of extreme warmth

The recent spate of frigid air comes on the heels of 2019, a poster year for Alaska’s amplified climate-driven warming. The state recorded its warmest month on record, warmest summer on record and warmest year on record. Anchorage’s Ted Stevens Anchorage International Airport hit 90 degrees for the first time on record.

From 1952 to 2000, only 12 nights in Anchorage failed to dip below 60 degrees. That happened nine times in 2019 alone. Anchorage had never seen more than four days hit 80 degrees in a year. In 2019, there were eight.

A winter that still bears shades of climate change

The dome of cold influencing Alaska at present doesn’t contradict the irrefutable warming Alaska’s been undergoing. In fact, the lack of record cold fits into the trend of fewer cold extremes as baseline temperatures warm.

“I would argue this is exactly what we would expect in a warming world,” Thoman said. “At 65 [degrees] north [latitude], it’s going to get cold. What we’re seeing … it’s not at historic levels. What we now call ‘really cold’ was ‘modest cold’ half a century ago.”

The cold has aided a rapid recovery of Bering Sea ice, whose extent was previously at record low levels.

“The ice there didn’t form until late in the season,” said Mark Serreze, director of the National Snow and Ice Data Center. “If you look at where you were in September in Point Barrow, there wasn’t ice for hundreds of miles.”

While the ice has recovered to near-normal levels, it is “surprisingly thin,” Thoman said.

The thin ice is more brittle, leaving it more susceptible to springtime storms. When these storms barrel through, it won’t take as much to dash the ice into smaller pieces.

“If we get into a sustained stormy pattern, that ice could get chewed up in a hurry,” Thoman said.

Across the Arctic more broadly, September is the climatological low point for sea ice; by October, a decrease in daylight and cooling temperatures foster its growth as winter approaches.

Last season’s summer sea ice extent tied for its second-lowest coverage observed during the satellite era (1970 onward), “reinforcing the long-term downward trend in Arctic ice extent,” according to the National Snow and Ice Data Center.

As for what the recent surge in sea ice means for the upcoming season, Serreze says, “We’ll sort of have to wait and see.”