Environment Canada says all areas can expect extreme cold, with windchills ranging from -30C to -40C this afternoon.
Many areas may also see an additional 15 to 30 centimetres of snow by Tuesday night, along with blowing snow creating treacherous road conditions.
Exposed skin could freeze in less than five minutes in these conditions, the federal weather agency warns.
Environment Canada Warning Preparedness Meteorologist Geoff Coulson says temperatures didn't drop as significantly as expected because of the squall activity. He says the concern now continues to be the blizzard and wind chill warnings.
Coulson says this weather system should continue through today and tonight into tomorrow morning before diminishing.
The following warnings reflect the varying intensity of the snow and wind expected across these areas:
BARRIE, ORILLIA, COLLINGWOOD, COLDWATER, MIDLAND AREAS
- Blizzard Warning
- Wind Chill Warning
BRACEBRIDGE, GRAVENHURST AREAS
- Blizzard Warning
PARRY SOUND, ROSSEAU, HUNTSVILLE, BAYSVILLE, HALIBURTON, MINDEN, ALGONQUIN PARK AREAS
- Snow Squall Warning
INNISFIL, NEW TECUMSETH, ANGUS AREAS
- Blowing Snow Warning
- Wind Chill Warning
ORANGEVILLE – GRAND VALLEY – DUFFERIN COUNTY
- Blowing Snow Warning
- Wind Chill Warning
NEWMARKET, GEORGINA, UXBRIDGE, BEAVERTON AREAS
- Wind Chill Warning
OWEN SOUND, BLUE MOUNTAINS, HANOVER, DUNDALK AREAS
- Blizzard Warning
- Wind Chill Warning