Weather tracker: unusual cold and snow spreading across North America

Temperatures in Canada dropped by as much as 20C below normal this week

Significant cold is spreading widely across North America this weekend, having already affected northern and western parts so far this week.

During the night of 9 November, temperatures across central and western provinces of Canada, as well as many western states of the US, plummeted to widely at least 10C (50F) below normal, with some parts of Canada seeing temperatures as low as 20C (68F) below normal.