What does Grain Rain mean?

The specific meaning is a folk proverb. Spring rain comes when the spring valley is harvested. It is very hot in midsummer, always accompanied by cooling in autumn, and it is very cold everywhere in winter. This is the song of the twenty-four solar terms.

Twenty-four solar terms refer to 24 specific seasons in the solar calendar, which are formulated according to the change of the position of the earth on the ecliptic (that is, the orbit of the earth around the sun), and each solar term corresponds to a certain position that the earth reaches every time it runs 15 on the ecliptic.

Twenty-four solar terms are a knowledge system formed by observing the movement of the sun in a year and understanding the changing laws of the four seasons, climate and phenology in a year. It divides the sun's annual trajectory into 24 equal parts, and each equal part is a solar term, starting from beginning of spring and ending with the great cold.

Solar terms refer to the twenty-four solar terms, which is a supplementary calendar formulated by China in ancient times to guide farming, and is the crystallization of the long-term experience and wisdom of the working people of the Chinese nation.

Since China was an agricultural society in ancient times, agriculture needed to have a strict understanding of the operation of the sun, and farming was carried out entirely according to the sun. Therefore, the "twenty-four solar terms" that reflect the solar cycle alone are added to the calendar as the standard for determining leap months.