Thursday, December 5th 2019, 4:15 pm - Welcome to winter, Canada.
It's a dubious distinction, but a fact of winter in Canada: The start of the cold season means someone has to be the first to hit -40ºC.
This year's first-to-forty title was awarded this week in Nunavut, when Shepherd Bay recorded a 'brisk' -41ºC temperature on December 4. With the wind chill, it felt more like -56.
Sitting on the shores of the body of water of the same name, the Shepherd Bay airport is one of Canada's research and radar stations, rather than a regularly-inhabited site. It's also got some coldest-temperature cred: The site recorded the coldest temperature in all of Canada last winter.
Here's how cold it got this winter across Canada. This winter's national cold spot belongs to Shepherd Bay, in Nunavut, with -48.8°C. 🥶 #winter #Canada #WxTwitterPatrick Duplessis on Twitter
It also makes the top ten on the list of coldest temperatures ever recorded in Canada. A −57.8ºC reading in February of 1973 good enough to land it in seventh place overall.
Despite the recent record chill, when you look back over the past 40 years of observations, it's another part of the country that's traditionally reigned supreme when it comes to the coldest temperatures. Between 1980 and 2019, sites in the Yukon were the coldest in the country 24 times, with Nunavut only capturing the title 9 times, and the Northwest Territories scoring 5. Honourable mentions go to Saskatchewan and Quebec, who each took the lead in one of the forty years.
Why has the Yukon typically been colder than Nunavut, even though the newer territory stretches farther north? It comes down to the type of air mass.
In the winter, air over the Yukon typically becomes extremely dry, allowing temperatures to plummet to near -50ºC at times by January and February. The Canadian Arctic's archipelago nature generally means water is never very far away. While temperatures still get frigid, increased moisture content has a moderating impact on the air and keeps it from getting quite as cold as the drier, 'continental' air mass.
The air that pushed Shepherd Bay to the -40 mark will continue its trek south into the weekend and early next week, dropping daytime highs into the -20s for parts of the eastern Prairies.