The meteorological services in both the United States and Canada have intensified their warnings in the face of polar temperatures that may reach 50 degrees below zero.

The state of Maine in the northern United States, in particular, is expected to witness a severe drop in temperature to 51 degrees below zero, according to a bulletin issued by the National Weather Service for the Caribou area near the Canadian border.

The National Weather Service for the Caribou area said, "It is a historic polar cold" unprecedented on the scale of a "whole generation" and is "something not witnessed especially in northern and eastern Maine since 1982 and 1988."

It pointed out that in parts of the northeastern United States and this area of New England, temperatures under the influence of icy winds may "reach their lowest levels in decades or even an unprecedented level."

On the other side of the border, a polar cold warning was issued in eastern Canada, according to the Ministry of Environment, which indicated the risk of frostbite within minutes.

The apparent temperature reached 41 below zero in Montreal on Friday afternoon. It may drop to 50 degrees below zero in the northern areas of Quebec.

White smoke, known as "sea smoke of the Antarctic region," rose above the St. Lawrence River due to the bitter cold passing over the unfrozen waters. Meanwhile, in Montreal, strong winds hit the few passersby downtown.

In the capital Ottawa, visibility was almost zero on Thursday night into Friday due to snowfall accompanied by strong winds.

Cold temperatures and winds in the United States are expected to peak on Friday night to Saturday, especially in Boston and New York, before starting to rise on Sunday.