Different places, it snows normally in the southern hemisphere in June. In China, it happened in history. There have been six snows in the Yangtze River valley and Fujian in the south of China. According to the records of Jinxi County, Jiangxi Province, A.D. 1653, "In summer and June in Jinxi, at noon on a hot day, heavy snow suddenly fell, and jade scales shone in the air, but not in front of the eaves". Fujian 166 1 year "Jian 'ou County Records" records: "Jian 'ou is cold in June, with the first frost and the fourth rain and snow." In modern times, "Six Heroes in the Snow" is not uncommon. 1981may 3 1 Sunday morning, the weather changed suddenly in Guancenshan area of Shanxi province. At first, the wind was strong and the temperature dropped rapidly. Then the overwhelming medium and high clouds moved slowly, covering the sky tightly. Near noon, snow suddenly floated in the sky. The snow is getting bigger and bigger, and it falls to the ground like goose feathers. The once-in-a-century heavy snow didn't stop until 3 pm on June 1 Sunday. The snowfall reached about 50 mm, and the snow melted completely after three days. At 4 o'clock in August 1987, Shanghai also experienced unexpected snowfall. This day is June 24 of the lunar calendar, which is the hottest time in the local area. However, the falling snow not only eliminates the heat, but also makes people have to wear thick clothes to keep out the cold. According to the analysis of meteorologists, the snowfall was due to the rapid drop of temperatures at altitudes of 3,000m and 5,000m to minus 4-7 degrees after a thunderstorm. This high-altitude cold air meets a lot of warm and humid water vapor on the ground, and the cold and warm air collides fiercely. Cold air prevailed, so a lot of snowflakes fell in the sky. This abnormal weather phenomenon is mostly caused by the invasion of strong cold air at high altitude in summer: in the year of abnormal climate, cold air is entrenched above 3000 meters above sea level, which makes the temperature in some areas drop below zero. Coupled with the rise of warm and humid air in the surface layer, cold and warm air meet, resulting in a short-term "timely assistance" weather.