🔗 Share this article Arctic Blast Tightens Hold on Canada as US Records Most Unseasonably Mild Christmas in History. A prolonged deep freeze has enveloped a bitter and extended period of frigid weather, with readings persisting in the minus 20 to minus 40 Celsius range for an extended duration. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature in half a century. Consecutive Nights Below -40C In addition, the locales of Mayo and Dawson suffered through 16 consecutive nights dipping under the minus 40 Celsius threshold, with Mayo experiencing a low of -50.4C at the start of the week. Whitehorse similarly reported a series of ten nights when temperatures dropped below -30C. This Arctic air mass pushed further southward over the festive period. On Christmas Day, overnight temperatures in Edmonton fell below -28C. Boxing Day was expected to bring readings no higher than -20 Celsius across many regions, from Edmonton in the west to Quebec in the east. Expected to Continue Through Early January This harsh winter weather is expected to continue into the new year. 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. This extended freeze is the result of a stationary polar vortex 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 gradually, enabling milder Pacific air to move across the United States and penetrate southern Canadian regions. Stark Contrast Compared to Stateside Temperatures Meanwhile, in a dramatic contrast, areas of the United States saw the hottest December 25th in their history as readings skyrocketed 15 to 30 degrees Celsius above normal. For numerous locations, the weather resembled a spring day in April or May than late December. A number of states broke historical records for December 25th warmth. Oklahoma City, Oklahoma, reached 25 degrees Celsius on Christmas, exceeding the old record of 22C from 1982. Metropolitan areas such as Austin, Dallas, and Charlotte also logged readings above 25 degrees Celsius. High-Pressure System Sustains High Temperatures Unseasonable heat is predicted to persist for the remainder of the week and beyond, with abnormal warmth projected to move across the southeastern US in the coming days. This heat is being driven 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. Descending air compresses and adiabatically warms, enabling abnormally high temperatures to develop.