What is the solar term?
Data expansion:
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; Celebrate every year on Gregorian calendar 10 year1October 23rd-24th. After entering the first solar term in first frost, the scene of late autumn is obvious, and cold air moves southward more and more frequently. The first frost does not mean "frost", but refers to the sudden drop in temperature and the large temperature difference between day and night. On the national average, "first frost" is the season with the largest temperature difference between day and night in a year.
In the first frost season, it's all over. From the morning, the sun went down to the ground, Yin Qi began to condense, and the first frost weather became colder and colder. 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 terms are characterized by cold weather in the morning and evening, hot weather at noon, large temperature difference between day and night, and obvious autumn dryness. The solar terms in the first frost mainly include the customs of enjoying chrysanthemums, eating persimmons, climbing high and overlooking, and tonic.
Meteorological changes:
The "first frost" solar term is characterized by cold weather in the morning and evening, hot weather at noon, large temperature difference between day and night, and obvious autumn dryness. On the national average, the first frost is the season with the largest temperature difference between day and night in a year. After entering the first first frost solar term, the cold air activities affecting our country became more and more frequent, and the temperature difference between day and night increased rapidly. Especially in Jiangnan and South China, the temperature fluctuation is more and more obvious; Some areas in northwest and northeast China have shown the scene of "cold wind and fallen leaves" in early winter.
During the first frost period, it usually lasts from late June 10 to1early October 10. As dry and cold air gradually dominate the whole country, warm and humid air is marginalized, and many weather with characteristics of summer and early autumn exits, so the weather is relatively simple. Before and after beginning of winter, there were often strong winds and cool weather, and some places entered winter in a short time.
Agricultural activities:
After the first frost solar terms, cold air activities become more frequent, and the temperature difference between day and night becomes larger. The "first frost" solar term has nothing to do with "first frost", which does not mean that entering the first frost solar term will lead to "first frost". In fact, "frost" does not fall from the sky, but the water vapor on the ground condenses when it meets cold air due to temperature difference changes.
There is no concept of "first frost" in meteorology. Generally speaking, the first frost in autumn is called "first 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 a frost-free period. In the first frost season, most parts of the north have been harvested in autumn.
Even cold-resistant onions can't grow any longer, because "the first frost can't support onions, and the longer they grow, the more empty they are." In the south, it is the peak season of "Sanqiu". Only single-season hybrid rice and late rice are harvested, and early-season wheat and early-season rape are planted. Picking cotton, pulling cotton stalks, ploughing and soil preparation.