Will it be cool in early autumn? How long will it be cool in early autumn?

How long does it take to cool down in beginning of autumn? After the Millennium, it will officially cool down.

The Millennium is the fifteenth solar term among the twenty-four traditional solar terms in China, and it is the solar term that indicates temperature. At this time, one month has passed in beginning of autumn, and the weather has gradually stabilized, and the temperature has continued to drop. Dew is water droplets condensed by water vapor on the ground or near-earth objects due to the temperature drop. So the Millennium actually indicates that the weather is getting cold.