There is typically autumn weather during Bailu period, when wild geese begin to migrate to the south and birds start to stock food for the long winter time. Hot summer is gone. However, it could be still warm in south China. It is different in the Yangtze River and Huaihe River valleys where it is usually humid during this period, as the saying goes: "It's unusual to see ten continuous sunny days." The reason is that at this time cold wind blows southward from the north, while warm and moist wind comes from the south, and they meet in the region, resulting in the rain. The locals call it Bailu rain, which is important for the growth of autumn crops in the region.
This is also the season that people may be exposed to various diseases like nasal disease, asthma, and bronchitis. Too much seafood or cold, spicy, or greasy food may not be good for health, but food containing more vitamins is good for your diet since the weather is getting drier after Bailu.