Northern Canada has been gripped by a bitter and extended period of frigid weather, with readings persisting in the minus 20 to minus 40 Celsius range for multiple weeks. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, its coldest December temperature since 1975.
In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights dipping under the minus 40 Celsius threshold, with the temperature in Mayo bottoming out at -50.4 degrees Celsius at the start of the week. Whitehorse also recorded ten separate nights when the cold dipped under -30 Celsius.
This Arctic air mass pushed further southward through Christmas week. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.
December 26th was anticipated to usher in readings no higher than -20 Celsius through a wide swath, encompassing cities from Edmonton to Quebec.
The frigid conditions are predicted to linger for the foreseeable future. Authorities have cautioned about potential power failures in the Yukon in the coming days, as its energy infrastructure faces unprecedented demand from historically high electricity consumption.
The prolonged chill has been caused by the Arctic vortex settling across the northern part of the continent this month, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north gradually, enabling milder Pacific air to move across the United States and penetrate southern Canadian regions.
Meanwhile, in a dramatic contrast, areas of the United States saw historically high temperatures for Christmas as the mercury climbed roughly 15 to 30 degrees above typical averages. Across wide regions, the atmosphere was more akin to late spring rather than the end of December.
Several states set Christmas Day temperature records. In Oklahoma, Oklahoma City hit 25C on Tuesday, surpassing the previous peak of 22C set in 1982. Metropolitan areas such as Austin, Dallas, and Charlotte were also among those that recorded temperatures above 25C.
Warmer-than-normal conditions are forecast to last on December 26th and into the weekend, with abnormal warmth projected to move across the southeastern US in the coming days.
The warmth has been fuelled by a powerful high-altitude ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. Such a configuration results in a widespread high-pressure system over a large portion of North America, effectively capping warm air at lower altitudes. As air sinks through the atmosphere, it compresses and heats further, fostering the buildup of exceptional warmth.
A geospatial analyst with over a decade of experience in terrain modeling and environmental data visualization.
