What does Yun Zheyue mean on August 15?

"On August 15th, Yun Zheyue, it snows and lights on the 15th day of the first month" is an agricultural proverb circulating in China. It is the weather forecast experience summarized by the working people in our country in the long-term production practice, which reflects the echo relationship between holiday weather.

It means that on the Mid-Autumn Festival on the 15th day of the eighth lunar month, if the sky is covered by clouds (cloudy or rainy) and the full moon cannot be seen, then the 15th day of the first month of next year will be a cloudy or snowy day. According to the data, on the day of the Mid-Autumn Festival in 2006, Beijing and other areas turned cloudy and cloudy, and the Mid-Autumn Festival began in Yun Zheyue in the evening, and then it turned cloudy and sunny.

There was a heavy snow in the early morning of the Lantern Festival on the fifteenth day of the first month of 2006, and it stopped gradually after noon, but it was still cloudy to cloudy and the cold wind roared, which just verified the accuracy of this agricultural proverb again.

The reason is precisely because the weather has a corresponding rhythm relationship. Rhythm means that after a certain weather appears, the corresponding weather will appear in the next few days. The duration of this rhythm varies from 30 days, 60 days, 90 days, 120 days, 150 days, 180 days and 240 days.

According to the lunar calendar, "Yun Zheyue on the 15th of August, snow lanterns on the 15th of the first month" is exactly the rhythm of 150 days. According to historical data, whenever the Mid-Autumn Festival is cloudy, cloudy or rainy, it will be cloudy or snowy on the fifteenth day of the first month of next year.