There’s no doubt that Toronto and much of the eastern Northern Hemisphere rang in a very cold New Year. But with global temperatures on the rise, what accounts for the frigid conditions we experienced?
Conor Anderson is a graduate student in the Environmental Science doctoral program at U of T Scarborough. As part of his doctoral studies he has looked at Toronto’s climate record, which is the longest record available in Canada.
He spoke to his supervisor, Professor William Gough, about whether it’s been an unusually cold winter in Toronto and how global warming may be playing a role in how cold it’s been.
William Gough: Toronto and much of North America experienced a period of intense cold in late December and early January. As part of your doctoral research you have looked at Toronto’s climate record. Is this year unusual?
Conor Anderson: I think the answer to this question depends on what you call unusual. Toronto’s weather is heavily influenced by the polar jet stream. This jet stream, which flows roughly from west to east with some movement to the north and south, occurs where relatively mild air from the continental northern hemisphere meets cold air from the arctic. So our winter weather tends to swing between really cold and slightly less cold as the jet stream moves to the north and south of us.
Having a burst of polar air hang around the city isn’t really out of the ordinary. That said, this last cold snap in December and early January ranks among the top ten longest and coldest in the past 30 years, so it was a nasty one. When we look at the monthly average temperature, December 2017 ranked 40th coldest out of 178 Decembers on record. If readers are curious how I came up with these numbers, they can check out the details on my blog.