Phenological Significance of beginning of autumn in the Twenty-four Solar Terms

In ancient China, beginning of autumn was divided into three periods: "A cool breeze blows gently; Second, wait fo

Phenological Significance of beginning of autumn in the Twenty-four Solar Terms

In ancient China, beginning of autumn was divided into three periods: "A cool breeze blows gently; Second, wait for the white deer to be born; Third-class chilling. "

Cool wind: People will feel cool when there is wind. The wind at this time is different from the hot air in summer.

White dew falls: The earth will be foggy in the morning.

Cicada chirping: Cicada chirping in autumn is also chirping.

In this solar term, the sun moves from Cancer to Leo (longitude 135). Looking at the sky at night, you can see that the bucket handle of the Big Dipper points in the direction of Tiangan "Shen" (southwest). The day when it was handed over to beginning of autumn was July of the lunar calendar, which was also called "Shen Yue Day". In beginning of autumn, the sun is at declination of+16 19', which is much more southerly than +23 26' from summer to sun, so the daytime in Beijing is shortened to 14 hours and 04 minutes (15 hours from summer to sun).

The weather is still very hot. After beginning of autumn, there are still "crouching" and "autumn tigers" still exist. So we should pay attention to heatstroke prevention. However, a leopard cannot change his spots. There is a "beautiful day" when it is hot at noon and cool in the morning and evening, and "one autumn rain is cold and ten autumn rains are frost."

Beginning of autumn has arrived, but not in autumn. The division of climatic seasons should be based on the "average climate temperature", that is, the local average temperature is below 22℃ for five consecutive days, which is the real autumn. China is a vast country. Although the climate varies from place to place, most areas have not yet entered the autumn climate, and the last days of dog days are still the third day after beginning of autumn.

Especially in the south of China, this solar term is still a hot summer. At the same time, because the typhoon and rainy season are about to pass and the temperature is even hotter, TCM calls the period from beginning of autumn to the autumnal equinox "long summer".