White dew of the 24 solar terms

White dew is the 15th solar term in the "24 solar terms", the third solar term in autumn. The end of the Shen month and the beginning of the unitary month. The sun reaches longitude 165 degrees; It is celebrated on September 7-9 in the Gregorian calendar. "White dew" is an important solar term reflecting the growth of cold in nature. As the cold air turned to attack, there was sunshine during the day and it was still hot, but the temperature fell soon after evening, and the temperature difference between day and night gradually widened.

To the white dew, the summer monsoon gradually replaced by the winter wind, the cold air turned to attack, coupled with the southern shift of the direct sun point, the northern hemisphere sunshine time is shorter, the light intensity is weakened, the ground radiation heat dissipation is fast, so the temperature drop speed is gradually accelerated. White dew basically ended the hot summer days, the weather gradually turned cool, cold dew condensation. The ancients used four times with five elements, autumn is gold, golden white, to describe the autumn dew, so the name "white dew".