What is the solar term for the white dew to be frost?

The Millennium is the fifteenth of the twenty-four solar terms, and it is the end of the full moon in the calendar and the beginning of January. The time is from September 7th to 9th every year in Gregorian calendar, when the sun reaches 165 degrees.

"Twenty-four solar terms" said: "August Festival ... Yin Qi is getting heavier and heavier, showing white." As the weather gets colder and colder, you will find many dewdrops on the ground and leaves in the morning, which is named after the water vapor condenses on them at night. The ancients used four seasons with five elements, and autumn was golden and golden white, so white was used to describe autumn dew. The Millennium actually indicates that the weather is getting cold.