Brief introduction of first frost.

The first frost is the eighteenth of the twenty-four solar terms. Fight with your fingers; The solar calendar is 210; Celebrate every year on Gregorian calendar 10,1October 23-24. The first frost is the last solar term in autumn and the transition from autumn to winter. 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 first frost is the18th solar term among the 24 solar terms, and the sun reaches the longitude of 2 10 degrees. The first frost is also the last solar term in autumn, and the temperature in many places has dropped to 0 degrees. The water vapor in the air will freeze into frost on the ground, showing small ice needles and hexagonal flowers. The number also began to decline, insects stopped eating and began to prepare for hibernation.

Wu Cheng, a scholar in the Yuan Dynasty, compiled Twenty-four Solar Terms, which divided the first frost into three stages: one was the sacrifice of the jackal; Second, the vegetation is yellow; Three stings are salty. At this time, jackals and other animals began to catch prey for the winter; The leaves are all yellow and falling; Hibernating animals also hide in caves and go into hibernation without food.

rural activity

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.