The Beginning of Autumn is an important solar term among the twenty-four solar terms, marking the turning point of the season and the beginning of autumn.

1. Overview of solar terms:

The Beginning of Autumn is the 13th of the 24 solar terms in the lunar calendar. It usually appears on August 7 or 8 in the Gregorian calendar. The specific date is determined according to each year. Calculated when the sun's ecliptic longitude reaches 135° after the summer solstice. The Beginning of Autumn marks the beginning of the waning of Yang Qi, the weather gradually turns cooler, and the characteristics of autumn begin to appear.

2. The sun reaches 135° of ecliptic longitude:

The Beginning of Autumn is a solar term determined based on the position of the ecliptic longitude of the sun. When the sun reaches 135° of ecliptic longitude, it means the beginning of autumn officially begins. At this moment, the position where the sun shines directly on the earth moves from the north to the southern hemisphere. The sunlight in the northern hemisphere gradually decreases, corresponding to the gradual drop in temperature.

3. Natural phenomenon:

At the beginning of autumn, the temperature in most areas begins to drop significantly, and there are more clouds in the sky. At this time, tropical cyclone activity is frequent, which can easily trigger weather phenomena such as typhoons and heavy rains. In terms of farmland, the beginning of autumn is a critical period before the harvest of crops.

4. The mood of autumn is getting stronger:

After the beginning of autumn, the mood of autumn is getting stronger, the weather gradually becomes cooler, and the temperature difference between day and night increases significantly. The plant begins to prepare to enter a dormant state, the leaves gradually turn yellow and red, and most of the fruits begin to ripen. People can feel the pleasant climate in autumn and the joy of harvest.

5. People’s customs and activities:

The Beginning of Autumn is an important node in traditional Chinese festivals. People will have various celebrations and sacrificial activities on this day. At this time, people eat specific foods, such as Liqiu cakes and persimmons, which symbolize blessings and a good harvest. At the same time, after the beginning of autumn, people will also start to make some preparations for autumn and winter, such as pickling food and storing winter supplies.

Summary:

As an important solar term among the twenty-four solar terms, the Beginning of Autumn marks the turning point of the season and represents the beginning of autumn. It is not only an important node in the movement of the sun and natural changes, but also closely connected with people's lives and customs. After the Beginning of Autumn, the mood of autumn becomes stronger, and people can enjoy the pleasant autumn climate, the joy of harvest and traditional festival customs.