🔗 Share this article

An intense cold spell has seized a severe and lengthy Arctic outbreak, with readings persisting between -20C and -40C for weeks. A reading of -55.7 Celsius was logged in Braeburn, Yukon, on Tuesday, its coldest December temperature in nearly five decades.

Enduring Chill Below -40C

Meanwhile, Mayo and Dawson endured sixteen nights in a row below -40C, with Mayo experiencing a low of -50.4C at the start of the week. Whitehorse also recorded ten separate nights when readings fell to minus 30 degrees or lower.

The bitter chill extended its reach south over the festive period. On Christmas Day, overnight temperatures in Edmonton fell below -28C.

Boxing Day was expected to bring lows of at least -20C across many regions, from Edmonton in the west to Quebec in the east.

Expected to Continue For Days to Come

The frigid conditions are predicted to linger through the start of January. Officials have warned that the Yukon could face electricity outages soon, as the system endures record-high pressure from record-high energy demand.

The lengthy cold snap originates from a stationary polar vortex above Canadian territory through December, allowing bitter Arctic air to spill south. In the coming week, forecasts indicate this cold air will pull back northward allowing more temperate air from the Pacific to sweep across America and reach into portions of southern Canada.

Pronounced Disparity Compared to Stateside Temperatures

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. For numerous locations, the weather resembled a spring day in April or May than late 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. Urban centers like Austin, Dallas, and Charlotte, North Carolina were also among those that recorded temperatures above 25C.

Atmospheric Ridge Fuels Warmth

Unseasonable heat is predicted to persist 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 unseasonable temperatures are powered by a strong upper-level ridge reaching from the arid southwest across the continent, establishing a classic heat-dome pattern. This pattern establishes a broad area of high pressure blanketing a significant part of the landmass, effectively capping warm air at lower altitudes. As air sinks through the atmosphere, it compresses and heats further, enabling abnormally high temperatures to develop.