Frost’s Descent is the 18th solar term of the year, which is also the last solar term in autumn. It falls on October 23rd this year. As one could guess from its name, Frost’s Descent means the weather is becoming colder and colder and frost is beginning to appear. But in fact, frost doesn’t descend from heaven to the earth; frost consists of white ice crystals of frozen water vapor near the ground. In the lower reaches of the Yellow River region, frost first appears in late October or early November, the period of Frost’s Descent. As Frost’s Descent comes, plants that can’t bear the cold stop growing and begin to wither away. The world is filled with the atmosphere of late autumn.

However, frozen frost refers to the damage to plants caused by low temperatures, which fall below 0℃ within a short time. The temperature is so low that the water content in plants begins to freeze and the metabolizing process is damaged. If the relative air humidity is too low, there may be no white frost at all, but frozen frost happens too. People usually call the invisible white frost “black frost.”

Therefore, Frost’s Descent is different from frozen frost. Frost’s Descent is only a solar term while frozen frost often damages plants. Where there are no plants, there is no frozen frost.