A cold air mass has settled over the region, leading Environment Canada to extend the Extreme Cold Warning that was issued on Sunday.
The mercury is expected to hit a frosty -30 to -33 C overnight Tuesday, with wind chill values ranging from -35 to -41.
The unseasonably cold weather is expected to stick around into the weekend.
The average daytime high for this time of year is -5 C, with the average overnight low sitting around the -15 C mark.
Extreme cold puts everyone at risk.
Dress warmly. Dress in layers that you can remove if you get too warm. The outer layer should be wind resistant.
Cover up. Frostbite can develop within minutes on exposed skin, especially with windchill.
If it's too cold for you to stay outside, it's too cold for your pet to stay outside.