“Bailu,” or the White Dew, is the 15th of 24 solar terms. After experiencing months of hot days, the cool autumn finally arrived accompanied by the "bailu." During bailu, the temperature gap between day and night gradually increases. As the cool autumn breeze drives away the warm air, the weather gradually turns into a "golden period" for outdoor activities. The three bailu pentads refer to birds, according to the ancient Chinese. At the starts of bailu, migratory birds like the wild geese and swallows will fly southward, and resident birds will begin to store food for the upcoming winter.