Rare noctilucent clouds appeared over Mohe City in northeast China's Heilongjiang Province from the night of June 15 to the early hours of June 16. After 9 p.m., the horizon remained bright, with clouds glowing like flowing ribbons in silver-white and pale-blue shades. The phenomenon usually appears in Mohe from June through July, when lasting twilight around the summer solstice, known as “white night,” makes high-altitude clouds visible.