In more than 100 years of Anchorage history, weather stations have never recorded a single 90-degree reading. If current forecasts hold, it could happen multiple times in the coming days.

With the combined forces of climate change that has disrupted temperature trends around the state, a remarkable dearth of ice in the Bering Sea and weather patterns generating a general heat wave, Alaska is facing a Fourth of July unlike any before. Anchorage has canceled its fireworks display because of wildfire concerns, city officials are worrying about air quality and forecasters expect temperatures to rival those in Miami.

“This is unprecedented,” Anchorage’s mayor, Ethan Berkowitz, said. “I tease people that Anchorage is the coolest city in the country — and climatically that is true — but right now we are seeing record heat.”

By any measure, the numbers are unusual. Alaska had its warmest March on record — in some places 20 degrees above normal. Once all the data is tabulated, it is likely to be the second-warmest June on record.

The highest temperature ever recorded at Anchorage’s official station was 85 degrees, while other stations in the area have gone a couple of degrees higher. Bob Clay, a meteorologist with the National Weather Service, said forecasters expected a high-pressure system to push temperatures well into the 80s starting on Thursday and potentially reach the 90-degree threshold in parts of the Anchorage area Friday, Saturday or Sunday.

While the weather has disrupted fireworks plans, Anchorage will still proceed with a Fourth of July pancake breakfast, a community parade and a festival with food vendors. A local Reddit thread was advising overheated residents to put jugs of ice in front of their fans, though a second thread warned those who didn’t already have a fan: “They are sold out everywhere. EVERYWHERE!”

Anchorage has now had 34 days in a row of above-average temperatures — “an exceptional run,” said Brian Brettschneider, a climatologist at the International Arctic Research Center. In Kotzebue, on the shores of northwestern Alaska, that above-average trend has extended for 105 days.

Alaska is experiencing many of the effects of a heating planet, as the nation’s fastest-warming state, according to the Fourth National Climate Assessment. The state’s temperatures are rising at twice the global average rate, with spring temperatures averaging about 2 to 5 degrees warmer than those of half a century ago.

One of the more dramatic changes in the state is the retreat of ice on the Bering and Chukchi Seas, which this year disappeared weeks earlier than normal in some areas. Ice reflects sunlight more than open water, which can absorb it and contribute to warmer air temperature above the surface. Surface temperatures on the seas are about 4 degrees above normal, while some areas are departing the norm by 10 degrees.

“For sea surface temperatures, that’s just astronomical,” said Rick Thoman, a climate specialist at the Alaska Center for Climate Assessment and Policy.

Thoman worries about the impact on communities that depend on hunting and fishing for survival, sometimes with the aid of ice. “Our communities are resilient, but things are happening so fast,” he said.

Wildfires this year have not been abnormally extreme, but they have consumed about 650,000 acres, which would match a typical full year. Last weekend, the National Weather Service issued its first Dense Smoke Advisory for the Anchorage area, with officials warning of both health and visibility problems caused by the plumes from the Swan Lake Fire that has spent a month charring the Kenai Peninsula south of the city.

Along with the fireworks cancellation in Anchorage, the Alaska State Fire Marshal has banned the sale and use of fireworks in much of the state. Still, with the heat rising and conditions dry, officials were also expecting fresh wildfires that could ignite by other methods.

“We could be up and running with fires here in the next couple days,” said Beth Ipsen, a spokeswoman with the Bureau of Land Management.

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