To farmers the Start of Autumn is especially important. It is said that if it thunders on the day of the Start of Autumn, corps will fail in winter. If it is sunny on the day of the Start of Autumn, the weather will be favorable and the crops will do well. If northern wind blows before Start of Autumn, it will probably rain afterwards. If northern wind blows after Start of Autumn, there will most probably be a winter drought. In the ancient feudalist society of China, the emperor, accompanied by his officials, would hold an autumn welcoming ceremony on the day of the Start of Autumn. Autumn is also the season for war affairs. Thus, you can tell how important the weather on the day of Start of Autumn is.

Source: Weather China