Central and Eastern Canada are bracing for a return of frigid weather as yet another arctic air mass invades the region, bringing wind-chill warnings and plummeting temperatures.
Wind-chill warnings are in effect from northern Manitoba through northwestern Ontario, and in parts of central and western Quebec.
Temperatures in northern Manitoba are expected to feel like –50 C.
In Toronto, temperatures will drop steadily throughout the day, reaching a low of –21 C overnight, but will feel like -30 C with wind chill.
The City of Toronto issued an extreme cold weather alert Monday, triggering additional services for the homeless.
"That Arctic air will be here for the next three to five days," said CBC meteorologist Jay Scotland. "Bitter cold is on the way. Not as cold as last time, but colder than normal."
Earlier this month, an arctic air mass caused by a polar vortex brought bitterly cold winds to parts of the U.S. and Canada.
In Toronto, the extreme chill led to flight delays and cancellations at Pearson airport, when a ground stop was issued to deal with the temperatures.
Snow squall watches are also in effect for parts of southern Quebec and Ontario, including London and Sarnia. Snowfall in the southwestern Ontario area could reach 15 centimetres, so Environment Canada is warning drivers about low visibility.
Meanwhile, temperatures in Western Canada this week have been unseasonably warm, reaching 4 C in Edmonton yesterday.