When is the starting point of autumn?

Traditionally, the "beginning of autumn" of the 24 solar terms is used as the starting point of autumn. Every year on August 7th or 8th, when the sun reaches 135° of ecliptic longitude, it is the "beginning of autumn" among the twenty-four solar terms;

In our country, the "beginning of autumn" of the twenty-four solar terms is traditionally regarded as The beginning of autumn. Entering autumn means that rainfall, humidity, etc. tend to decrease or decrease. In nature, the yin and yang qi begin to change, the yang qi gradually retreats, the yin qi gradually grows, the climate turns from hot to cold, and all things gradually decline as the cold qi grows.

According to modern meteorology, autumn in the northern temperate zone ranges from August 23 (summer heat) to November 22 (light snow); autumn in the southern temperate zone ranges from February 19 (rain in the northern hemisphere) to May January 21st (Little Full in the Northern Hemisphere).

Phenology

Autumn is the harvest season, and many plants mature in autumn. In the autumn season, in nature, the yin and yang qi begin to change. The yang qi gradually retreats and the yin qi gradually grows. The climate turns from hot to cold. All things grow with the cold and gradually decline. This is the season of alternating heat and cold. As the temperature gradually drops, the leaves of many deciduous perennial plants will gradually change color, wither, and fall, leaving only branches to survive the winter.

Annual herbaceous plants will reach the end of their lives and wither to death. Seasonal transition covers many aspects of climate characteristics. It would be inaccurate to use temperature alone as the criterion for determining the onset of autumn. The most obvious change in autumn is that the leaves of grass and trees turn from lush green to yellow and begin to fall, and crops begin to mature.