An Arctic air mass continues to cast a deep freeze over large swaths of Canada this morning, plunging many parts of the country into the negative double digits and bringing cold air and wind chill warnings.

Temperatures in Manitoba are forecast to be particularly harsh.

In Winnipeg, a Tuesday high of –21 C drives home the severity of its wind chill warning. The extreme chill is forecast to be as low as –40 C in the morning, and daytime highs over the next week aren’t expected to get any warmer than –20 C.

Staff at the city’s homeless shelters have been scramling to open up emergency beds for those caught out in the bitter cold.

Blizzard and snowfall warnings were in effect along the west coast of Newfoundland, where drivers were warned to give themselves ample time to reach morning destinations due to blowing snow and poor visibility. About 15 centimetres is expected to fall on St. John’s vicinity.

A high of –17 C is forecast for parts of Quebec, with a wind chill in the morning making it feel closer to around –30 C. Extreme wind chills were in effect late Monday night for the Abitibi regions, courtesy of a northwest flow from Eastern Quebec bringing strong winds and cold air. Environment Canada issued a warning saying the uncomfortable conditions would spread into Central Quebec and persist in the St Lawrence Valley throughout the week.

Parts of Northern Ontario are under wind chill warnings due to the Arctic air mass and gusts of around 15 km/h, which could bring wind chill values as low as –55 C in the morning, though daytime heating is likely to bring that up closer to a still-blistering –45 C.