What to wear in Tunchang in the coldest time?

Thin cotton-padded clothes, knitted sweaters, etc. Tunchang, located in Hainan Province, is characterized by long summer without winter, high temperature and rainy weather, and distinct dry and wet seasons. The four seasons have not changed much. The annual average temperature is 23.0 ~ 23.6 degrees, and the coldest average temperature is 16℃ ~ 18℃. So it is enough to wear thin cotton-padded clothes and knitted sweaters for more than ten degrees.