Basic Information of White Dew: White Dew is the 15th of the 24 Solar Terms, the third solar term in the fall, and the end of the month of Shen and the beginning of the month of You in the dry calendar. The Do refers to the decalogue; the sun reaches 165 degrees of yellow longitude; and the festival is held on September 7-9 of the Gregorian calendar. "White Dew" is an important festival reflecting the growth of cold in nature. As the cold air turns from defense to offense, the sun is still hot during the day, but the temperature drops quickly in the evening, and the temperature difference between day and night gradually widens.

Time to white dew, summer winds are gradually replaced by winter winds, cold air to attack, coupled with the sun's point of direct sunlight to the south, the northern hemisphere sunshine time becomes shorter, the intensity of light is weakened, the ground radiant heat dissipation fast, so the temperature drop is gradually accelerated. White Dew basic end of the sultry heat of the summer days, the weather gradually turned cool, cold dew condensation. The ancients to the four seasons with five elements, autumn is gold, gold white, white to describe the autumn dew, so the name "white dew".

Historical origin of the White Dew:

Twenty-four seasons, is the calendar that indicates the natural rhythmic changes and the establishment of the "December building" of a particular season. There are four seasons in a year, three months in spring, summer, fall and winter, and two seasons per month, each with its own unique meaning. White Dew is the fifteenth of the twenty-four solar terms, which indicates the end of the Mengqiu season and the beginning of the mid-autumn season, and is an important solar term reflecting changes in temperature in nature. According to the interpretation of "White Dew" in "The Seventy-Two Waiting Periods of the Moon", "the moisture in the soil and water condenses into dew, and autumn is gold, and the gold is white, and the white is the color of the dew, and the air starts to get cold".

White Dew phenomenon:

White Dew Festival, the summer is gradually disappearing, the autumn high and refreshing, the fragrance of Dan Gui, geese and swallows and other migratory birds began to fly south to avoid the cold, a variety of birds began to store food for the winter.

"The geese come and the birds return." After the White Dew, migratory birds, which are most sensitive to the climate, migrate en masse. The geese begin to fly from the north to the south, and the southern basilisks also fly back to the north, all kinds of birds begin to store food for the winter. Proverb has a cloud: "white dew autumn wind night, geese fly south a line", "the autumn robin hypnotizes people to sleep, at the summer sunflower smile, white dew swallow return and come geese, the autumn equinox cinnamon fragrance full of garden". Therefore, migratory birds like geese are regarded as a symbol of the arrival of autumn.