Today ushers in the 16th of the 24 solar terms: the autumnal equinox.

        In a year, there are only two solar terms that can divide the day and night equally. One is the spring equinox and the other is the autumn equinox: the spring equinox is one minute, and then the days get longer and longer; The autumnal equinox is one minute. Since then, the night is getting longer and longer. "At the autumnal equinox, yin and yang are half the same, so day and night are cold and summer are flat."

        Autumnal equinox, even autumnal equinox. One word divides autumn into two parts: one is the equal time of day and night, and the other is the climate from hot to cold. At this time, the sky is high, the clouds are light, the dew is cold and the wind is clear, the teal geese are high, and the osmanthus is fragrant. The arrival of the "autumnal equinox" marks the formal entry of cool autumn in most parts of China. The days are short and the nights are long, and the coolness is strong day by day. Especially at night, it is cool overnight. In addition, when the cold air going south meets the gradually decaying warm and humid air, it will produce a process of precipitation again and again, and the temperature will also drop. It is the so-called "one autumn rain and one cold".