What are the rules for the entry and exit of plums?

The rules of plum blossom entry and exit can be divided into modern meteorological standards and traditional methods.

1, meteorological plum entry standard

In the first five days of May, the subtropical high is at the ridge line of120 E ≥18 N, and the average daily temperature is ≥22℃ in at least three of the five days. There must be four rainy days in the first five days after the plum blossom (including rainy days measured by suburban weather stations); If the plum rains are segmented, the temperature after each segment of plum rains shall be ≥22℃.

Plum production standard

Before and after the meiyu ended, the ridge line of subtropical high jumped from north to 26 N or north between 120- 130 E, with the daily average temperature ≥27℃ and the highest temperature ≥30℃, and there was no rain for more than 6 days. It will rain continuously in the future, which belongs to "summer rain" and not to "plum rain". The traditional entry and exit of plums is related to heavenly stems and earthly branches. The main basis is as follows

2. In the traditional method of our country, the judgment of plum entry and plum exit is based on the combination of solar terms and branches. According to the calendar, the first third day after mango seeds is plum blossom, and the first last day in Xia Hou is plum blossom. If the weather on the awning day is C, it is designated as entering the plum blossom, and if it is not in the shallow summer, it is designated as leaving the plum blossom.

For example, there was a slight summer heat on July 7th 1993, and then it fell on July 13, so the plum blossom date of 1993 is July 13. July 7, 200 1 year is a slight summer heat, and July 19 after the slight summer heat is not an earthly branch. According to the calendar, the plum blossom date of 200 1 should be July 7th instead of July 19.