"Frost" is the beginning of a frost season in a year, and also the transition from autumn to winter. At this time of the festival, cold air activities are frequent, temperature changes are intensified, the temperature difference between day and night increases, and at night it often drops below zero degrees Celsius. Water vapor in the air condenses on the ground and vegetation, forming tiny white ice needles or hexagonal frost.
According to the observation of nature, the ancients divided "frost fall" into three stages: one stage is a jackal offering sacrifices to animals; Second season grass and trees fall yellow; Three waiting insects are salty. It means that at this time, jackals and wolves hunt frequently, vegetation withers faster, and insects begin to hibernate. However, "frost fall" brought the last touch of autumn after all. Maple leaves became orange red after the baptism of autumn frost. Under the sun, the forests were dyed like rosy clouds; Although the withered lotus in the pond has been beaten by frost and its leaves wither and droop, its stems still stand upright, becoming another beauty in late autumn.
