How climate change is causing more frequent warm winter temperatures in Canada

One extreme weather expert says mild winter temperatures — like the recent warm spell in Ontario — are becoming more frequent across Canada due to climate change.

Blair Feltman, head of the Intact Centre on Climate Adaptation at the University of Waterloo, says that although it’s hard to attribute individual weather events to climate change, the destabilization of the polar vortex caused by global warming is contributing to atypical extreme temperatures.

Feltman says the resulting warmer temperatures in the winter could cause more extreme rain and snowfall events at times of the year when they’re not expected, which may result in worsening flood conditions.

Doug Gillham, a meteorologist with The Weather Network, says most of the country is now seeing an extended winter break and warmer-than-normal temperatures after seeing a front-loaded winter in December.

However, Gillham says colder-than-normal winter temperatures are expected to return in late January or early February.

Parts of southern Ontario have seen unseasonably warm temperatures in recent days, and Environment Canada has issued a mix of rainfall and freezing rain warnings for a number of regions in the province.

The weather agency says regions under freezing rain warnings can expect 10 to 15 centimetres of snow mixed with ice pellets by Thursday morning. In comparison, other regions could see another round of 15 to 25 centimetres of rainfall by the evening.

Some local conservation authorities are warning the public to stay away from waterways as water levels are expected to rise due to the rainfall as well as melting snow.

This report was first published by The Canadian Press on Jan. 4, 2023.