Extreme weather events are becoming more frequent in Alaska, and other climate report takeaways

Landslides, heavy snowfall, flooding and wildfires aren’t uncommon in Alaska. But as the oceans and atmosphere grow warmer, such extreme events and disasters are becoming more frequent across the state, a new report says.

The Alaska Center for Climate Assessment and Policy at the University of Alaska Fairbanks International Arctic Research Center this week released the report, titled “Alaska’s Changing Environment 2.0.″ The report contains contributions from dozens of scientists and Indigenous experts and dives into various long-term climate trends, focusing on changes that have been affecting Alaska communities, infrastructure and wildlife in the past five years.

The air temperature in Alaska, consistent for most of the 20th century, began to rise in the late 1970s and since then has climbed more than 3 degrees, according to the report. While the last five years — still warm compared to the historical average — didn’t show temperatures as high as in the early 2010s, the resulting extreme events related to weather and climate became more frequent, said Rick Thoman, ACCAP’s climate scientist and the report’s science lead.

“Whether it’s Merbok-type storms, or extreme snow in Anchorage, or fatal landslides caused by excessive rain and winds — these extreme events have really picked up the pace here in the last five years,” Thoman said.

Anchorage sees more heavy snow

One consequence of the warmer climate that Anchorage residents can observe is more heavy-snowfall events.

Over the past three winters, the city has seen at least one snowstorm that brought more than a foot of snow in a day, according to the report.

In December 2022, three significant storms dumped snow on the city in a short span of nine days. Then in 2023, a heavy snowstorm happened early in the season — in November — and led to plowing challenges, business closures and commuters unable to make it to work or leave their homes.

The report highlighted how heavy snow loads prompted the collapse of dozens of commercial building roofs in Anchorage, and put over 1,000 business properties at risk during the winter of 2023-24.

As oceans warm, more water evaporates into the atmosphere, and when the temperature in Anchorage is below freezing, it results in more snow — spurring more frequent heavy snowstorms, Thoman said.

“It does make sense that yes, we live in a warming world, and we’re seeing these big, extreme snowfall events when all the pieces come together,” Thoman said.

Meanwhile, in Fairbanks, winter rain has become more frequent over the past 20 years. The city, known for consistently snowy and cold winters, now sees at least one — and sometimes several — winter rainfall events each season, according to the report. Local transportation agencies have adjusted how they maintain roads, and the school district adjusted its calendar to build in weather days.

Disastrous landslides and storms

Alaska has also seen an increase in fatal landslides, avalanches, severe storms and floods in recent years, the report said.

Since 2020, the state has declared nearly three dozen disasters related to weather or climate — about double the total between 2014 and 2019, according to the report. A third of those were also declared as federal disasters, the report said.

“These events pose great risk to infrastructure, food security, public health and safety,” the report said. “Rural communities, most only accessed by air or water, are especially vulnerable.”

In Southeast Alaska, that meant more frequent — and deadly — landslides.

In August 2015, three people died in a landslide in Sitka; in December 2020, two died in a slide near Haines; a November 2023 slide near Wrangell killed six; and in August 2024, one person died and three were injured in a slide in Ketchikan. The landslides also damaged property, disrupted transportation and required weeks or months of cleanup, the report said.

Most of these landslides were associated with high-intensity rainfall as well as strong winds, Thoman said.

“You get completely saturated ground, and then you get the wind moving trees,” he said.

Thoman pointed out that landslides aren’t uncommon in Southeast Alaska, but the increase in fatalities is significant. Prior to 2015, the last fatal landslide in the region happened in the 1930s, he said.

“Something has changed in that regard for Southeast,” he said, and “it’s become a big problem for Alaska.”

[Previously: Southeast Alaska reckons with deadly landslides — and a future that promises more]

Glacial lake outburst floods, driven by the thinning of glaciers, are also an increasing hazard in the state, the report said. At the Mendenhall River in the Juneau area, outburst floods have been happening annually since 2011, with record floods in 2023 and 2024 that inundated streets and damaged homes.

For Alaska’s coastal regions, warming oceans that stay ice-free for longer lead to increasingly severe storms.

Typhoon Merbok developed over unusually warm weather in September 2022, the report said, and the typhoon’s remnants damaged houses and roads in about 40 communities on Alaska’s western coast. Most recently, a fall storm brought historic flooding the Kotzebue area.

Thoman said that the main trend influencing the storms’ severity is that sea ice is established later and later in the year, leaving the coast exposed to waves and winds.

“Not every year, say, in the 1970s would we have had significant ice in Kotzebue Sound by Oct. 20. But some years we would have,” Thoman said. “Would that have protected Kotzebue a little bit? Could well have.”

Thoman pointed out that even with severe weather events becoming more frequent, it is important to remember that every year might bring different conditions.

“As Alaska prepares for the future, in many things, we have a good idea of the long-term trends, but that year-to-year variability is not going away,” he said. “There’s still going to be years in Anchorage that get a lot of snow. There are going to be years that get a little bit of snow.”

Indigenous voices document changes

To track and understand changes across Alaska, scientists have been partnering with Indigenous observers and experts, the report said.

[New report highlights increased polar bear presence and challenging travel in Northwest Alaska as the Arctic warms]

Iñupiaq residents in northern and Western Alaska have been sharing their observations through the Alaska Arctic Observatory and Knowledge Hub, speaking about shifts in weather conditions and the impacts their communities have been experiencing as a result.

In the Kotzebue area, Bobby Schaeffer has been sharing his observations about how the changing climate has led to more difficult and dangerous travel, as well as postponed activities and altered hunting seasons.

Schaeffer said that the water around his town freezes later in the fall and the surface becomes unreliable for travel earlier in spring.

“It doesn’t take very long for it to get dangerous,” he said. “People fall in both times, both fall and spring. ... People have lost their lives because of trying to traverse across the ice.”

In another example, in the North Slope community of Kaktovik, the warming climate has led to an increased presence of polar bears, according to resident Carla SimsKayotuk.

During the summer, the ice retreats north, and while the majority of polar bears still stay on the ice, more and more of them come on land and stay there for longer, said U.S. Geological Survey research wildlife biologist Karyn Rode, who has been studying polar bears for several decades.

With the change, scientists have been looking at how polar bears are responding to human-related disturbances such as planes and boats, said Todd Brinkman, associate professor at UAF’s Institute of Arctic Biology.

Brinkman said that in normal conditions, when aircraft can stay above 1,500 feet, it doesn’t significantly affect the bears. However, when the ceiling is low and aircraft have to fly lower, there’s a greater opportunity for a disturbance and bears changing behavior.

The increasing proximity of polar bears to people can potentially lead to more tourism opportunities, but also to more human-bear conflicts, the report said. Brinkman said that for now, there is no data on interactions between humans and polar bears, but potential studies are on the table.

“The communities need to be part of this,” Brinkman said. “They need to really guide the research so whatever information we generate is useful to them, and it can help them make decisions.”