Snow and freezing temperatures have battered many parts of the U.S in January, with temperatures as low as -10 degrees Centigrade/14 Fahrenheit recorded in many States. In Idaho, the extreme weather led to a rare sighting of an Ice disk on the Snare River on January 22. An unusual natural phenomenon, ice disks occur in slow moving water in cold climates and can vary in size, with circles more than 15 metres (49 ft) in diameter observed. Credit: Daniel Ostler