Why is Battle of Red Cliffs a southeast wind?

It can explain the problem of water flow, yes, the river flows from southwest to northeast, but during the war, it does not go downstream, but goes upstream, on the south bank of Jiangdong and on the northwest bank. No one knows why the southeast wind blows. There is a saying that it was the winter solstice, the solar terms were handed over, and the yin and yang were reversed, so the south wind was blowing abnormally. However, there is no unified statement about when Battle of Red Cliffs happened.