What are the climatic characteristics of beginning of winter? What is the impact on agriculture?

In beginning of winter, the middle and lower reaches of the Yellow River began to freeze at11~1,which is consistent with beginning of winter time, but in the Yangtze River basin, the real winter is about half a month later than beginning of winter time. On the Qinghai-Tibet Plateau, "it is still cotton in midsummer in June, and it is mostly cold all year round"; Near the Tropic of Cancer from Guangzhou to Nanning, there are few days in winter. Xia Wudong, Governor of Hainan. Therefore, this solar term in beginning of winter does not apply to the whole country. The average daily temperature in the middle and lower reaches of the Yangtze River ranges from 10 to 13, and the rainfall ranges from 20mm to 40mm. Late rice harvest is busy. Winter wheat sowing began to sweep the tail.