Why has it been so cold in Canada this winter?

A hot topic, or shall I say “cool” topic of discussion this year has been the frigidly cold winter temperatures in southern parts of North America…but is this really unusual and why has it been so cold?

Typically, when there are very strong temperature differences between the northern Arctic areas and the south, a strong polar vortex, or a gigantic circular weather pattern around the North Pole keeps the cold air locked up north. However, this year, the temperature differences weren’t as great, allowing a jet stream of freezing arctic air to meander its way down south into many parts of North America that do not typically experience this level of cold.

This could all be caused by climate change, as a gradually warming arctic slowly reduces the temperature differences between parts of North America and our northerly neighbours. Whether this climate change is human-caused or natural variability remains a topic of debate and research. One thing’s for sure though: as climate change continues we can expect more meandering jet streams and as a result, more deep freezes in the years to come.