Arctic Blast Envelops Canada as America Sees Hottest Christmas on Record.

Northern Canada has been gripped by a bitter and extended period of frigid weather, with temperatures hovering in the minus 20 to minus 40 Celsius range for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, its coldest December temperature in nearly five decades.

Enduring Chill Below -40C

Meanwhile, Mayo and Dawson endured over two straight weeks of nights below -40C, with Mayo plunging to -50.4C at the start of the week. Whitehorse similarly reported a series of ten nights when temperatures dropped below -30C.

The deep freeze spread farther south 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, encompassing cities from Edmonton to Quebec.

Expected to Continue For Days to Come

The severe cold is forecast to persist into the new year. Authorities have cautioned about potential power failures in the Yukon soon, as the territory’s power grid comes under strain from historically high electricity consumption.

The prolonged chill has been caused by a stationary polar vortex 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 allowing more temperate air from the Pacific to sweep across the US and into parts of southern Canada.

Pronounced Disparity to American Heat

Conversely, sections of America recorded their warmest Christmas Day on record as temperatures soared about 15-30C above the seasonal average. In many areas, conditions felt more typical of 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, surpassing the previous peak of 22C set in 1982. Metropolitan areas such as Austin, Dallas, and Charlotte also logged readings above 25 degrees Celsius.

High-Pressure System Drives the Heat

Above-average warmth is expected to continue for the remainder of the week and beyond, with atypical high temperatures expected to spread into the south-eastern states later in the week.

The warmth has been fuelled by a strong upper-level ridge stretching from the southwestern deserts northward and eastward, which generates a heat-dome phenomenon. Such a configuration results in a widespread high-pressure system across much of the continent, effectively capping warm air at lower altitudes. As air sinks through the atmosphere, it compresses and heats further, enabling abnormally high temperatures to develop.