Personally, I think Beihai is good, Beihai is a subtropical maritime monsoon climate. Winter is not cold, summer is not hot, is really warm in winter and cool in summer. Temperature, light, rain source abundant, pleasant climate. The average annual temperature is 22.9℃. Beihai is located in the subtropics, the climate is warm and humid, the air is fresh, and the negative ion content in the air per cubic centimeter is as high as 2,500 to 5,000, which is 50 to 100 times higher than that of the inland cities; Beihai City also has the Weizhou Island, which has a warmer temperature than that of Beihai City, so I think it is more suitable for Beihai.
1, Hainan
Winter is very good, the air in all seasons ranked the best, Sanya long years pm2.5 in about 20. The downside is that it is hot in the summer, and the time available for living is only 3-5 months a year.
Beihai
2. In terms of climate alone, Beihai is very suitable in winter. Because it is not cold. But in summer it is not suitable, not only hot, but also long. So in summer it's only suitable if you go to the north.