Londoners stripped their pants for the annual “No Trousers on the Tube Day” on January 7, 2018. More than 400 Londoners braved frosty conditions when temperatures plunged to a chilly 3 degrees Celsius. This bizarre annual tradition which is in its ninth year in London, began as a small prank in New York almost 16 years ago, and has now spread to more than 660 cities.