5. According to experts, snowflakes are the accumulation of small ice crystals. Most snowflakes are not greater than 0.39 inches in width. The largest snowflake in the world, according to the Guinness Book of Records, has fallen on a ranch in Fort Keogh, Montana in January 1887. Rancher measured it and saw that it had a diameter of 15 inches, it is about the size of a flying disc for Frisbee.