🔗 Share this article Arctic Blast Envelops Canada as America Sees Most Unseasonably Mild Christmas in History. A prolonged deep freeze has enveloped an intense and prolonged cold spell, with temperatures hovering from 20 to 40 degrees below zero for multiple weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, marking its chilliest December reading in nearly five decades. Enduring Chill of Extreme Cold Meanwhile, Mayo and Dawson endured 16 consecutive nights colder than minus 40 degrees, with the temperature in Mayo bottoming out at -50.4 degrees Celsius at the start of the week. The capital, Whitehorse, likewise saw 10 nights when temperatures dropped below -30C. This Arctic air mass pushed further southward through Christmas week. On Christmas Day, overnight temperatures in Edmonton fell below -28C. Boxing Day was expected to bring lows of at least -20C across many regions, including Edmonton, Montreal, Ottawa and Quebec. Expected to Continue For Days to Come This harsh winter weather is expected to continue for the foreseeable future. There are warnings of possible electrical grid strain in Yukon territory over the next several days, as its energy infrastructure faces unprecedented demand from historically high electricity consumption. The prolonged chill has been caused by a stationary polar vortex over Canada for much of December, 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 America and reach into portions of southern Canada. Dramatic Difference Compared to Stateside Temperatures In stark contrast, parts of the US experienced the hottest December 25th in their history as the mercury climbed roughly 15 to 30 degrees above typical averages. For numerous locations, the weather resembled a spring day in April or May instead of the heart of winter. A number of states broke historical records for December 25th warmth. The capital of Oklahoma soared to 25C on Christmas Day, 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. Heat-Dome Effect Fuels Warmth Unseasonable heat is predicted to persist 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 strong upper-level ridge extending from the desert south-west towards the north and east, which generates a heat-dome phenomenon. This setup creates an extensive zone of high atmospheric pressure blanketing a significant part of the landmass, effectively capping warm air at lower altitudes. Sinking atmospheric air undergoes compression and additional heating, fostering the buildup of exceptional warmth.