On Monday evening the frigid weather is set to fall on the north-east US, where residents are still digging out from the week's deadly snowstorm.
In eastern Canada, the temperatures are expected to drop quickly throughout Monday. Freezing rain caused long airport delays in Toronto and Ottawa.
In New York City, temperatures are expected to drop to roughly -12C (10F) overnight.
Environment Canada's David Phillips told the BBC the rapid temperature drop expected - about 24 degrees centigrade in 24 hours in cities such as Toronto - means residents could be driving or walking on roads that are "like a rink of ice".
Cold temperatures could bring lows not seen in 20 years.
Some parts of Canada could see as much as 23in of snow over just a few days, Mr Phillips said.