As the saying goes, "August 15th, Yun Zheyue, the 15th day of the first month, it snows and lights up". What is the basis?

"August 15, Yun Zheyue, 15th day of the first month, snowing and lighting" reflects the echo relationship between holiday weather. Mid-Autumn Festival is a traditional folk festival in China. As the saying goes, the Mid-Autumn Festival is especially bright. On the night of Mid-Autumn Festival, the bright moon is in the sky, and the silver light shines on the earth. On this pleasant and quiet night, people get together to watch the bright moon and tell children stories about the Goddess Chang'e flying to the moon, osmanthus tree and Jade Rabbit. The echo relationship between the weather of these two traditional festivals has always been concerned by people. Over time, in many places, if the sky is covered with dark clouds on the night of August 15, then snowflakes often fly on the first month 15.

The echo relationship between the weather of these two traditional festivals has always been concerned by people. Over time, in many places, if the sky is covered with dark clouds on the night of August 15, then snowflakes often fly on the first month 15. So people summed up a popular weather proverb: "August 15th, Yun Zheyue, the 15th day of the first month, bright". Of course, the rhythmic activity of the atmosphere is a very complicated problem, which has its reasons, conditions, manifestations and many other aspects.

On the surface, "Yun Zheyue" and "Snow Lantern" are the echo phenomena of clouds and snow, but in essence they are the echo relationship of two cold air activities. In other words, if there is cold air activity around the Mid-Autumn Festival, it will cause the "Yun Zheyue" phenomenon. Then around the Lantern Festival, cold air will invade again, forming a situation of "snow hits the lights". Therefore, the proverb "August 15th, Yun Zheyue, the fifteenth day of the first month snows and lights are lit" is a reflection of the rhythmic activity of the cold air invading China for about five months.

Why are there two holiday weather days besides 150 days? It turns out that this is a manifestation of atmospheric rhythmic activity. The atmosphere of the earth is like a big band, with wind, clouds, rain, snow, thunder, electricity, fog and frost, as if the band had played a music with rich timbre. A certain weather process, which is obvious at a certain moment, reappears after a certain period of time under certain conditions, or manifests itself in other forms due to different seasons, just like the beat in music. On the surface, there is no direct evolutionary relationship between them, but in fact there is a certain relationship.