Large chunks of sea ice float just off the shore of Nome on February 12, 2025. Ben Townsend photo.

Record heat, poor sea ice define ‘weird’ western Alaska winter

Western Alaska experienced a particularly unusual winter marked by record heat, poor sea ice, persistent open water, and unusually low snowfall — conditions climate specialist Rick Thoman described in one word as “weird.”

The venerable climatologist says Nome’s all-time record high of 44 degrees on December 11 stood out to him. The December heatwave was followed by a dry spell that extended through the New Year, leaving large swaths of bare tundra. The low snowfall plagued regions across Alaska, leading to a rerouted Iditarod sled dog race. Just weeks before, Iron Dog snowmachiners traversed 60 miles of snowless tundra.  

“That was pretty remarkable. Not unprecedented, but pretty remarkable,” Thoman said. 

In early February, sea ice unexpectedly left the shoreline of Nome, revealing deep blue water that would normally be blanketed in bright white sea ice. 

An aerial view of Nome's shoreline showing large areas of open water on February 12, 2025. Ben Townsend photo.

Thoman said several factors contributed to the unstable and limited sea ice, including delayed formation, unseasonably warm periods, and wind patterns that pushed ice away from shore.

“It really wasn’t until January when we got some snow and some cold weather that allowed the sea ice to thicken up and get anchored,” he said. “So it’s forming later. Took a while for it to get cold enough to actually really start to grow that ice near shore.”

Thoman said Arctic sea ice extent – the area of ocean with at least 15% sea ice – for 2025 was the lowest on record, even less than the previous record lows set in 2017 and 2018. 

“There’s nothing even close to like that in the satellite era,” Thoman said.

He said the unusual weather, particularly low snowfall, could lend itself to earlier berry picking season, but that it raises concerns too.  

Arctic-wide maximum annual sea ice extent. Time varying average estimated by ordinary linear regression. Data from NSIDC, ACCAP graphic.

“If it winds up being a warm, dry late May, June, that allows the tundra to dry out more,” he said. “Then the wildfire risk increases.”

Thoman extended his concerns to salmon migrations later in the summer too. 

“We get another warm, dry summer like, say 2019, then all of a sudden we’ve got rivers that are too hot, the salmon don’t want to enter it,” he explained. 

Last fall, Thoman forecast a La Niña winter which typically comes with large amounts of precipitation. Looking back, he realized his forecast was wrong and said that the unpredictability is a symptom of climate change. 

“The reality is with all the changes that are going on, particularly with oceans warming globally, Alaska may be the canary in the coal mine that these things like El Niño, La Niña may not be as dominant a driver of our winter weather and climate as they used to be,” Thoman said. 

Thoman provides climate insights and reports through his website. His position at the Alaska Center for Climate Assessment and Policy is funded by the National Oceanic and Atmospheric Administration. A leaked memo sent by the Trump Administration to NOAA revealed plans to slash funding to the office Thoman works at. Final funding decisions will be made when Congress votes on a budget in the coming months.

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