In the northern parts of the US have established unprecedented frosts:
the temperature dropped below minus 30 degrees Celsius.
1. Ice bound trees along the shores of Lake Michigan in Chicago, Illinois, after a wind speed of 64 km / h, washed waves, and the temperature dropped to -10. (Scott Olson / Getty Images)
2. A woman waiting for a bus in Mayfield Heights, Ohio, December 13th. Frosts and heavy snowfall caused havoc on the roads and delayed flights. (Tony Dejak / AP)
3. Cars during a heavy snowfall in Merrillville, Indiana. Snow and cold weather caused problems on the roads in the northwest Indiana. (Jeffrey D. Nicholls / Post-Tribune via AP)
4. Ryan Shaw (left) and Jeff Messenger remove the snow from the track in Bowling Green, Ohio. (JD Pooley / AP)