Arctic Blast Envelops the Great White North as US Records Most Unseasonably Mild Christmas on Record.

An intense cold spell has seized a bitter and extended period of frigid weather, with temperatures hovering in the minus 20 to minus 40 Celsius range for weeks. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day since 1975.

Prolonged Freeze Below -40C

Meanwhile, Mayo and Dawson endured 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. The capital, Whitehorse, likewise saw ten separate nights when the cold dipped under -30 Celsius.

The deep freeze spread farther south over the festive period. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.

Boxing Day was expected to bring minimum temperatures of at least minus 20C across many regions, encompassing cities from Edmonton to Quebec.

Expected to Continue Through Early January

The frigid conditions are predicted to linger into the new year. Officials have warned that the Yukon could face electricity outages in the coming days, as its energy infrastructure faces unprecedented demand from record-high energy demand.

The lengthy cold snap originates from the Arctic vortex settling above Canadian territory through December, enabling a surge of icy Arctic winds to descend. Next week, the cold air mass is expected to retreat north slowly, permitting warmer Pacific winds to flow over the United States and penetrate southern Canadian regions.

Pronounced Disparity Compared to Stateside Temperatures

Meanwhile, in a dramatic contrast, areas of the United States saw historically high temperatures for Christmas as temperatures soared about 15-30C above the seasonal average. Across wide regions, the atmosphere was more akin to late spring instead of the heart of winter.

Multiple states established new Christmas temperature highs. The capital of Oklahoma soared to 25C on Christmas Day, exceeding the old record of 22C from 1982. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina were also among those that recorded temperatures above 25C.

Heat-Dome Effect Sustains High Temperatures

Above-average warmth is expected to continue on December 26th and into the weekend, with abnormal warmth projected to move across the southeastern US in the coming days.

The unseasonable temperatures are powered by a powerful high-altitude ridge extending from the desert south-west towards the north and east, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure across much of the continent, which holds warm air close to the ground. Sinking atmospheric air undergoes compression and additional heating, allowing unusually warm temperatures to build.