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The end of winter in North America brought chilly weather in many regions, and the cold and snow in Europe made news headlines. But the most unusual weather this winter is going on at the North Pole—with exceptionally high temperatures at the Arctic. Things are heating up where warmth is least expected.
The cold spell in the Northern Hemisphere is unusual, perhaps, but not exceptional. In general, cold waves are becoming less frequent. However, the warmth in the Arctic is extraordinary. During the month of February, temperatures surged into the mid-30s F—which is more than 50 degrees warmer than normal.
Keep in mind that at the North Pole, the Sun set on December 21, on the solstice, and would not rise again until the start of spring on March 20—a 3-month-long night. The normal temperature at the North Pole does not rise to freezing until late May and never rises above the 30s, even at the peak of summer.
The average temperature for the entire region above 80° north latitude rose to its highest February level since measurements began in 1958; this is also likely to be the highest temperature there in hundreds or even thousands of years.
According to Zack Labe, a climate scientist working on his PhD at the University of California at Irvine, “No other warm intrusions were very close to this. I was taken by surprise by how expansive this warm intrusion was.”
Although this is the most extreme example of polar warmth in winter, unusually warm weather has occurred there much more frequently in recent years than in the past. Robert Graham, lead author of a study published last July by the Norwegian Polar Institute, notes that this type of winter event occurred only four times in the decades from 1980 to 2010, “but has now occurred in four out of the last five winters.”
Meanwhile, some 400 miles south of the North Pole, the northern tip of Greenland has already been above freezing for 61 hours in this calendar year (as of late February), shattering its previous record for hours above freezing through April, which was set at 16 hours in 2011.
Although North America and Europe have had their share of cold weather this winter, most of the Northern Hemisphere has had average temperatures higher than normal, and this has resulted in the lowest extent of wintertime Arctic ice cover ever recorded (see Fig. 1).
And while 2017 was not as warm a year as 2015 or 2016 when averaged across the entire Earth, most locations experienced above-normal temperatures, including nearly all of North America (see Fig. 2).