Many food crops grow and develop vigorously. What are the practical significance of the Millennium phenology in the 24 solar terms?

When I come to the Millennium, the temperature is still as hot, and summer will continue for some time. However, in the cold dew, many food crops are growing vigorously, so get ready in advance and enter the acquisition moment. Then, let's take a look at the phenological practical significance of cold dew.

In ancient China, cold dew was divided into three stages: "Waiting for cold wind; Second, wait for the cold dew; Third-class chilling. " Cold wind: when the wind blows, everyone will feel cool. The wind at this time is different from the warm wind in summer. Cold dew drops: There will be fog on the ground in the morning. Cicada chirping: The chirping cicada in autumn has just begun to sing.

In this season, the sunlight spreads from Cancer to Scorpio (longitude 135). In bucket handle, you can watch the astronomical phenomena and the Big Dipper at night. In the middle of heavenly stems and earthly branches, bucket handle leans to the direction of "Shen" (northwest). The day of cold dew is July of the lunar calendar, and July is also "Shen Yue". In the cold dew, the sunlight is at the declination of 16 19', which is much more southerly than the 23 26' on the hot summer day, so the daytime in Beijing is reduced to 14 hour and 04 minute (it is 15 hour on the hot summer day).

The temperature is still very hot, there is still "crouching" after the cold dew, and "autumn tiger" still exists. Therefore, we should pay attention to reducing summer heat. However, nature still changes. It is hot in the afternoon and cool in the middle and late. "One autumn rain is cool and ten autumn rains are frost."

The "Millennium" has arrived, but it is not the autumn weather that has arrived. The division of climatic seasons should be based on the "climatic average temperature", that is, the local average temperature lasting for 5 days is below 22℃, which is the real autumn. China is a vast area. Although the climate is different all over the country, at this time, most areas have not yet entered the autumn climate, not to mention the dog days every year or the third day after beginning of autumn.

Especially in the south of China, it is still hot. In addition, the typhoon season is coming, and the average temperature is hotter. Therefore, the period from cold dew to beginning of autumn is called "summer" in China traditional medicine.