The 38 degrees Celsius measured in Siberia last year was officially recognized by the UN as a new record high for the Arctic.
The hottest temperature ever recorded above the Arctic Circle was on June 20, 2020 in the Russian town of Verkhoyansk, the World Meteorological Organization said.
This is the first time that the WMO has added record heat in the north to its archive, and it comes at a time of record temperature spikes around the world.
The chief of the WMO Archive of Weather and Climate Extremes said that the new record in the northern part of the planet sounded the alarm bells about the changing climate.
Verkhoyansk is north of the Arctic Circle and has had temperatures measured there since 1885.
The temperature was measured at a meteorological station during the extremely long heatwave in Siberia.
It said that the average temperatures in the summer in Siberia were up to 10 degrees above normal, which caused fires and sea-ice loss.
One of the three warmest years on record was in 2020 because of the heatwave.
Taalas said that last year saw a new record high of 18.3C for the Antarctic continent.
Death Valley in California is the world's hottest place and the WMO is still trying to verify the 54.4C recorded in 2020.
A new European temperature record of 48.8C was reported on the Italian island of Sicily this past summer, and its experts are working to verify it.
Taalas said the WMO's archive has never had so many simultaneous investigations.
There is a new category.
The world's highest and lowest temperatures, rain, hailstone, longest dry period, maximum gust of wind, and weather-related mortalities are tracked in the archive.
The dramatic changes in the region were recognized by adding record heat.
The pace of change in the northern part of the planet is more than twice the global average.
Randall Cerveny, agency weather expert, said that the investigation shows the increasing temperatures occurring for a climatically important region of the world.
The creation of a new category means that both polar regions are now represented.
The experts did not provide a previous record temperature for the region, but they did say that no temperatures of 38C or above had ever been measured there.
The lowest temperature ever measured above the circle was -93.9F on December 22, 1991 in Greenland.