What are the phenological characteristics of Xiaoxue solar terms?

The three phenological phenomena of light snow solar terms are: "The rainbow disappears at first, the sky rises and falls, and the winter comes." The ancients believed that in the spring of the season, the sun was flourishing and the sun was declining, so there would be a rainbow, while in the winter of Meng, the sun was flourishing and the sun was declining, so there was no rainbow, so it was said that "the rainbow could not be hidden." "When the weather rises, the earth's atmosphere drops" means that at this time, the sun in the sky rises, the yin on the ground begins to fall, and everything stops growing. "Three weathers prevent winter" means that the weather is colder at this time, the land is frozen, and people stay indoors. It can be seen that winter is a closed season.