What are the weather characteristics of cold dew in solar terms?

Cold dew is the17th solar term in the twenty-four solar terms, which is the end of the full moon in the dry calendar and the beginning of the full moon. The time point is when the sun reaches the longitude 195 (within Virgo) on the 8th or 9th of October every year in the Gregorian calendar. "Twenty-four solar terms" said: "September solar terms, dew will condense when it is cold." Cold dew means that the temperature is lower than that of the white dew, and the dew on the ground is colder and will soon condense into frost. In the cold dew season, Nanling and the vast area to the north have entered autumn, and the northeast and northwest regions have entered or are about to enter winter.

On this day, the daytime in Beijing has been shortened to 1 1 hour 29 minutes, and the sun height at noon has dropped to 44 09'. After the cold dew, the height of the sun continued to decrease and the temperature gradually decreased. White dew, cold dew and first frost all indicate the phenomenon of water vapor condensation, and cold dew is the transition from cold to cold. At night, looking up at the starry sky, you will find that the season of the starry sky changes, and the "Big Mars" (Scorpio Antares) representing midsummer has already set in the west. We can vaguely hear the footsteps in winter.

At this time, the temperature in most parts of South China continued to drop. The average daily temperature in South China is less than 20℃. Even in the areas along the Yangtze River, it is difficult for the mercury column to rise above 30℃, while the minimum temperature can be reduced to below 10℃. Except for a few valley lowlands, the five-day average temperature in the northwest plateau is generally lower than 10℃, which is already winter according to the standard of four seasons climate division. Thousands of miles away, first frost and Wan Li are snowing, which is very different from autumn in South China.