Polar vortex brings temperatures as low as -29 Celsius to US Midwest

Americans were forced to wrap up on Wednesday as a blast of Arctic air that came from a polar vortex brought dangerous and freezing weather to a large area of the country.

Steam billowed from Lake Michigan and ice formed on the water, as Chicago's streets froze.

You can see footage of the freezing conditions in the above video player.

The Midwest was the worst-hit region in the US, with temperatures dipping low as -18 Celsius.

Overnight between Tuesday and Wednesday, it dropped to -29 Celsius in Minneapolis.

With a wind chill factored in, temperatures were set to feel as low as -46 Celsius in Chicago and elsewhere in Northern Illinois on Wednesday, even though the real figure stood at -23 Celcius.


Officials planned to cancel classes for all 360,000 students in Chicago on Wednesday because of the subzero temperatures.

The cause of the big freeze - the polar vortex - was a large area of low pressure over the North Pole, which was rotating anti-clockwise around the stratosphere. Beneath this lay a dense layer of arctic air that was pushed south over the US.