Victory Day
One of the biggest outdoor parties took place on Victory Day. People had a very good reason to celebrate: Germany had surrendered to the Allied Powers, and WW2 was about to end. While fireworks exploded in Moscow, crowds gathered at Times Square.
The Russians took to the streets at 1 AM, still in their pajamas. Naturally, the British also celebrated. Above is a picture of a British woman dancing with an American soldier in London in May 1945. Similar scenes were seen across all Allied nations.