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. This week, the Yukon community of Braeburn saw the mercury drop to -55.7C, representing its most frigid December day in nearly five decades.

Prolonged Freeze in the Deep Minus Forties

Similarly, the communities of Mayo and Dawson experienced 16 consecutive nights colder than minus 40 degrees, with Mayo experiencing a low of -50.4C on Monday. Whitehorse also recorded ten separate nights when temperatures dropped below -30C.

The deep freeze spread farther south over the festive period. Christmas night saw Edmonton's temperatures plummet below minus 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.

Forecast to Persist 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 the territory’s power grid comes under strain from historically high electricity consumption.

This extended freeze is the result of the polar vortex remaining anchored over Canada for much of December, enabling a surge of icy Arctic winds to descend. The frigid dome is projected to gradually withdraw north slowly, permitting warmer Pacific winds to flow over the US and into parts of southern Canada.

Pronounced Disparity to American Heat

In stark contrast, parts of the US experienced 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 instead of the heart of winter.

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. Cities including Austin and Dallas, in Texas, and Charlotte, North Carolina similarly saw thermometers rise past the 25C mark.

Heat-Dome Effect Fuels Warmth

Unseasonable heat is predicted to persist on December 26th and into the weekend, with unseasonable heat forecast to sweep into the south-eastern states later in the week.

The warmth has been fuelled by a powerful high-altitude 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 across much of the continent, trapping warm air near the surface. Descending air compresses and adiabatically warms, fostering the buildup of exceptional warmth.