US winter storm: Almost 1m without power as temperatures could fall to -56C

A powerful Arctic storm is sweeping across much of the United States and Canada – with almost a million people left without power.

Thousands of flights have been cancelled – while temperatures could fall as low as -56 Celsius in places, amid warnings about the risk of frostbite.

The freezing weather has spread as far south as Florida and Texas – while some places are under more than ten feet of snow.