The first frost is the first of the 24 solar terms.

The first frost is the eighteenth of the twenty-four solar terms and the last solar term in autumn. Fight with your fingers; The solar calendar is 210; Salary will be paid every year on the Gregorian calendar 10,123-24 October. The first frost solar terms are characterized by cold weather in the morning and evening, hot weather at noon and large temperature difference between day and night.

Because "frost" is a manifestation of cold weather and large temperature difference between day and night, it is named "first frost", which means "sudden drop in temperature and large temperature difference between day and night". The first frost solar term, everything ends, ends, the sun goes down to the ground, and the yin begins to condense. The first frost does not mean "frost", but refers to the sudden drop in temperature and the large temperature difference between day and night. After the first frost solar term, the scene of late autumn is obvious, and the cold air goes south more and more frequently.

From the national average, the first frost is the season with the largest temperature difference between day and night in a year. The "first frost" solar term reflects the climatic characteristics of sudden drop in temperature, great change in temperature difference between day and night, and obvious dryness in autumn. The cold weather began with the first frost. The first frost doesn't mean you need first frost to enter this solar term. In fact, frost didn't fall from the sky. Frost is the condensation of water vapor on the ground when it meets cold air due to the change of temperature difference. The solar term "first frost" has nothing to do with first frost, they are not the same concept.

The solar terms in the first frost mainly include the customs of enjoying chrysanthemums, eating persimmons, climbing high and overlooking, and tonic. The first frost season is the turning point of autumn and winter climate, and it is also the transition of the spirit of the sun from being hidden. The key to health care should pay attention to "keeping out the cold outside and clearing heat inside". There is a folk saying that it is better to make up the first frost in winter. In autumn, the spleen and stomach are the foundation of the day after tomorrow. At this time, tonic is appropriate, especially strengthening the spleen and nourishing the stomach to nourish the day after tomorrow.