Beginning of autumn and the autumn solstice, who can explain?

On August 7th or 8th every year, beginning of autumn is considered as the time when the sun reaches 135. Twenty-four solar terms: "July Festival, set up a word to solve spring (beginning of spring). Autumn is also awkward, and this is the thing. " Beginning of autumn generally indicates that hot summer is coming and autumn is coming. After beginning of autumn, although the summer heat is hard to disappear for a while, there is still the afterglow of "autumn tiger", but the general trend is that the weather is getting colder and colder. Due to the different climates in different parts of the country, the start time of autumn is also inconsistent. In climatology, autumn begins with the day when the daily average temperature drops steadily below 22℃ every five days. This division method is in line with the local reality, but it is quite different from the date of beginning of autumn in the middle and lower reaches of the Yellow River. After beginning of autumn, early rice harvest, late rice transplanting and autumn crops entered an important growth and development period in central China. Autumn means that summer is cool and autumn begins. The ancients thought that beginning of autumn was an important moment at the turn of summer and autumn, and they always attached great importance to this solar term.

September 23rd is the "Autumn Equinox".

The "autumnal equinox" is a solar term representing seasonal changes. On the day of the "autumnal equinox", the sun is located at 180 degrees, and the sun is almost direct to the equator, and day and night are equal again. From this day on, the days in the northern hemisphere became shorter and the nights became longer.

The autumnal equinox is a solar term representing seasonal changes. On the day of the autumnal equinox, the sun is located at longitude 180 degrees, and the sunlight is almost direct to the equator, and day and night are almost equal. At this time, the waiting temperature in the southern region has generally dropped below 22℃, and it has entered a cool autumn. "An autumn rain and a cold". The cold air from the south meets the warm and humid air that gradually decays, resulting in repeated rainfall and the temperature dropping again and again. In the northern part of the northwest plateau, the daily minimum temperature has dropped below 0℃, and you can already see the magnificent snow scene flying all over the sky and the earth wrapped in silver.