Why is the last solar term spring?

Why is the last solar term in spring like this: Grain Rain is the last solar term in spring.

However, now is the busiest time for farmers. The spring rain is moderate, and the sun is dim and not hot. Now is the best time to sow seedlings. The twenty-four solar terms of the lunar calendar is a supplementary calendar for guiding farming in ancient China, and it is the crystallization of long-term experience and wisdom of working people in ancient China.

The significance of solar terms

Beginning of spring, Changxia, beginning of autumn and beginning of winter are used to reflect the seasons, which are the beginning of the four seasons. A year is divided into four seasons: spring, summer, autumn and winter. The vernal equinox, autumnal equinox, summer solstice and winter solstice are divided from an astronomical point of view, reflecting the turning point of solar height change. The five solar terms of slight summer heat, great summer heat, slight cold and severe cold reflect the change of temperature and are used to express the degree of heat and cold in different periods of the year.

The four solar terms of rain, Grain Rain, light snow and heavy snow reflect the phenomenon of precipitation, indicating the time and intensity of rainfall and snowfall. The three solar terms, White Dew, Cold Dew and First Frost, on the surface reflect the phenomenon of water vapor condensation, but in essence reflect the process and degree of gradual temperature drop. When the temperature drops to a certain extent, the water vapor condenses and the temperature continues to drop, which not only increases the condensation, but also gets colder and colder. When the temperature drops below zero degrees Celsius, water vapor condenses into frost.

Xiaoman and Miscanthus reflect the maturity and harvest of related crops, while Jingzhe and Qingming reflect the natural phenology, especially Jingzhe, which shows the return of spring through the lightning recovery in the sky and underground.