What are the climatic characteristics of beginning of autumn?

After beginning of autumn, the north wind began to blow in many areas of China, and the south wind gradually weakened. The small north wind brings coolness to people. "The white dew falls at the second hour", because the sun is still strong during the day, and the cool breeze blows at night to form a certain temperature difference between day and night. In the morning, the water vapor in the air condenses into crystal dew and falls on outdoor plants. "Three-time chilling cicada", the cicada at this time, with plenty of food and suitable temperature, sings proudly on the branches blown by the breeze, as if to tell people that the hot summer has passed. After waiting for 5 days, beginning of autumn 15 days, it gradually got cold.

Cooling is a climate trend. According to beginning of autumn Sanhou's description, this may happen when the climate is cold. Beginning of autumn solar terms indicate that hot summer is coming and autumn is coming. When beginning of autumn arrived, many parts of our country were still in hot summer. After beginning of autumn, although the summer heat is hard to disappear for a while, there is still the afterglow of "autumn tiger", but the general trend of the weather is getting colder and colder.

The temperature difference between morning and evening is gradually obvious, which is often very hot during the day and relatively cool at night. . Of course, due to the different climates in different parts of the country, the real start time of autumn is also inconsistent. In reality, there are several divisions of beginning of autumn: among the 24 solar terms, beginning of autumn, the fourth solar term, is the beginning of autumn; In astronomy, according to the earth's orbit around the sun, the "autumnal equinox" is regarded as the beginning of autumn; In climate statistics, for example, 65438+ 10 is the most Leng Yue, July is the hottest month, March-May is spring, June-August is summer, and September-165438+10 is beginning of autumn. On the daily average temperature, when the daily average temperature for five consecutive days is ≤ 22℃ ~ ≥ 10℃, the first day will be the start date of autumn. Because of the great differences in geographical location, surface and altitude in different regions of China, it is impossible for all regions to enter autumn at the same time when they are in beginning of autumn.