Deep Freeze Grips Canada as US Records Hottest Christmas Ever.

Northern Canada has been gripped by a severe and lengthy Arctic outbreak, with thermometers lingering in the minus 20 to minus 40 Celsius range for an extended duration. On Tuesday, Braeburn in the Yukon recorded -55.7C, representing its most frigid December day since 1975.

Consecutive Nights Below -40C

Meanwhile, Mayo and Dawson endured 16 consecutive nights below -40C, with the temperature in Mayo bottoming out at -50.4 degrees Celsius on Monday. The capital, Whitehorse, likewise saw 10 nights when temperatures dropped below -30C.

The bitter chill extended its reach south through Christmas week. In Edmonton, the Christmas overnight low dipped under -28 degrees Celsius.

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.

Forecast to Persist For Days to Come

The frigid conditions are predicted to linger into the new year. There are warnings of possible electrical grid strain in Yukon territory in the coming 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, which funnels frigid northern air southward. 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.

Dramatic Difference with US Warmth

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. In many areas, conditions felt more typical of April or May rather than the end of December.

Multiple states established new Christmas temperature highs. In Oklahoma, Oklahoma City hit 25C on Tuesday, 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.

Atmospheric Ridge Fuels Warmth

Unseasonable heat is predicted to persist through Boxing Day and the days ahead, with abnormal warmth projected to move through the American Southeast soon.

The unseasonable temperatures are powered by a robust atmospheric ridge stretching from the southwestern deserts northward and eastward, which generates a heat-dome phenomenon. This setup creates an extensive zone of high atmospheric pressure over a large portion of North America, trapping warm air near the surface. Sinking atmospheric air undergoes compression and additional heating, allowing unusually warm temperatures to build.