A dramatic weather divide is unfolding across North America, with extreme cold gripping much of Canada while parts of the United States experience record-breaking warmth. Northern Canada has been under a prolonged deep freeze for weeks, and the unusual conditions are impacting daily life and infrastructure.
Extreme Cold in Canada
Temperatures in Northern Canada have been consistently between -20C and -40C in recent weeks. Braeburn in the Yukon recorded -55.7C on Tuesday, marking its coldest December temperature since 1975.
The cities of Mayo and Dawson have each experienced 16 consecutive nights below -40C, with Mayo reaching -50.4C on Monday. Whitehorse has also seen 10 nights where temperatures dropped below -30C. The cold has spread southward, with Edmonton experiencing overnight temperatures below -28C on Christmas Day and lows of at least -20C expected across regions including Edmonton, Montreal, Ottawa, and Quebec on Boxing Day.
Officials in the Yukon have warned of potential electricity outages in the coming days as the territory’s power grid faces strain from record-high energy demand. The prolonged cold is attributed to the polar vortex remaining anchored over Canada for much of December, allowing Arctic air to move south.
Record Warmth in the US
While Canada shivers, parts of the United States are experiencing unusually mild temperatures. Christmas Day saw record highs in several states, with temperatures 15-30C above the seasonal average. Conditions in many areas felt more akin to April or May than late December.
Oklahoma City, Oklahoma, reached 25C on Tuesday, surpassing its previous Christmas Day record of 22C set in 1982. Austin and Dallas, Texas, and Charlotte, North Carolina, also recorded temperatures above 25C. Above-average warmth is expected to continue through Boxing Day and into the coming days, with unseasonable heat forecast to spread into the south-eastern states.
This warmth is being driven by a strong upper-level ridge extending from the desert south-west towards the north and east, creating a “heat-dome” effect. This pattern creates high pressure, trapping warm air and causing it to compress and heat further as it sinks.
What’s Next?
The current pattern is not expected to hold indefinitely. The cold air mass over Canada is forecast to gradually retreat north next week, potentially allowing milder Pacific air to move across the US and into parts of southern Canada. However, the timing and extent of this shift remain uncertain.
Frequently Asked Questions
What is the polar vortex?
The polar vortex is a large area of low pressure and cold air surrounding both of the Earth’s poles. It typically remains contained, but can sometimes become unstable and send cold air southward.
What is a heat dome?
A heat dome is a pattern in the atmosphere where high pressure traps hot air in a particular area. As air sinks under the high pressure, it compresses and heats up, leading to unusually high temperatures.
How long is the cold expected to last in Canada?
The severe cold is forecast to persist into the new year, although the cold air mass is expected to retreat north gradually next week.
How do these extreme weather events impact communities and infrastructure in the affected regions?
