"First Frost" solar terms are characterized by cold weather in the morning and evening, hot weather at noon, large temperature difference between day and night, and obvious dryness in autumn. On the national average, First Frost is the time of year when the temperature difference between day and night is the largest. After First Frost, the cold air activities affecting China become more and more frequent, and the temperature difference between day and night increases rapidly. Especially in South China and South China, the fluctuation of temperature is more and more obvious; And parts of the northwest and northeast have already shown a "cold wind and fallen leaves" early winter scene.

During First Frost, generally from late October to early November, as dry cold air gradually dominates the world, warm and humid air has been marginalized, and many weather with summer and early autumn characteristics withdraw, and the weather is relatively simple. Before and after the start of winter, there is often a strong wind and cooling weather, and some places have entered the winter in a short time.

After First Frost, cold air activities become more frequent, and the temperature difference between day and night becomes larger. "First Frost" has nothing to do with "frost descent", and it is not a "frost descent" when you enter the Frost Descent. In fact, the "frost" does not fall from the sky, but the water vapor on the ground is condensed by cold air due to temperature differences. In meteorology, there is no concept of "frost", generally speaking, the first frost in autumn is called "early frost" or "first frost", and the last frost in spring is called "late frost" or "final frost"; The interval from the last frost to the first frost is the frost-free period. When Frost comes, the autumn harvest has already finished in most parts of northern China. Even the hardy scallions can no longer grow, because "the frost can not afford the scallions, the longer the more empty." In the south, it is the "three autumn" season, single-season hybrid rice and late rice are harvested, planting early-crop wheat and early-crop rape; The cotton was picked, the cotton straw was pulled, and the land was tilled.

First Frost, the last solar term of autumn, people also attach great importance to it, and there are customs such as removing evil spirits and sweeping tombs, in order to pray for good weather and a happy life. For example, in some places such as Yantai, Shandong province, people will go to the western suburbs to welcome the frost on the day of frost. In Gaoming district of Guangdong Province, there is a custom of "sending taro ghosts" before First Frost. In some parts of China, red persimmons are eaten during First Frost. In the local people‘s view, this can not only keep warm, but also strengthen the muscles and bones, is a very good frost food. At the same time, when the frost comes, it is the time when the chrysanthemum is in full bloom. At this time, the folk will hold a chrysanthemum meeting to express their love and reverence for the chrysanthemum. In addition, there is a folk saying that "making up for winter is better than making up for frost." Therefore, in the season of First Frost, the folk have the food customs of "pot mutton", "pot sheep‘s head" and "welcome frost rabbit meat".