What is the origin and meaning of cold dew solar terms?

1, cold dew is the phenomenon of water vapor condensation, and the cold dew solar term is the seventeenth solar term in the twenty-four solar terms of the lunar calendar, which indicates the official start of the autumn season.

2. Every year on the 8th or 9th of Gregorian calendar 10 year 10, when the sun reaches the longitude of the Yellow River 195 degrees, it is a cold dew solar term.

In ancient times, dew was considered as a symbol of cold weather. The solar term of the Mid-Autumn White Dew is "dew and white", but it is already "dew and cold", and it will condense into frost when it is cold in the season and autumn.