The record temperature was recorded at Alert, a military base and weather station at the northern tip of Ellesmere Island in the Canadian Arctic, 817 kilometres from the North Pole.
The base, which sits on the 82nd parallel and intercepts Russian communications, is the northernmost permanently inhabited settlement on the planet.
Since the weather station became operational in 1950, the previous record high temperature was 20 degrees Celsius, on 8 July 1956.
“It’s an absolute record, we’ve never seen that before,” Armel Castellan, a meteorologist with the Canadian environment ministry, told AFP news agency.
Multiple high temperatures
The new record is part of a recent trend of warming, and high temperatures have reached 19 and 20 degrees on several occasions since 2012.
Two other records have been broken in recent days.
The temperature reached 21 degrees on Sunday and then 20 degrees on Monday, the first time the station recorded back-to-back days of highs of at least 20 degrees.
Such highs are “completely staggering,” Castellan noted, adding “for a week and a half we have had much higher temperatures than usual.”
It was also the first time a temperature warmer than 20 degrees has been measured anywhere north of the 80th parallel, or within about 1100 km of the pole.
Historically, the average July daily temperature in Alert is 3.4 degrees, with the average maximum temperature being 6.1 degrees.
Arctic heat wave
Scientists say an uncommon high pressure front over Greenland and winds from the south are making for high temperatures across the region.
“It is not exaggerated to call it an Arctic heat wave,” David Phillips, a senior climatologist at Environment and Climate Change Canada, told AFP.
“The north, from Yukon right to the Arctic islands, was the second or third warmest spring on record,” he said, adding that forecast models show “that is going to continue through July and then into August and early September.”
Scientists warned last year that the Arctic is heating up twice as fast as the rest of the planet.
Research published this year found rising temperatures impact changes in permafrost, snow cover, sea ice and ecosystems, among other indicators.
And, as meteorologists note, the new record is just one more of the high temperature records being broken around the globe ever year.
“It’s just one example among hundreds and hundreds of other records established by global warming,” said Castellan.