When is the coldest time in Shenzhen every year?

In this place of Shenzhen, it won't take long to wear cotton-padded clothes. It takes about a month to wear cotton-padded clothes. The coldest time is around the Spring Festival, and the temperature is 7-8 degrees. It will rain a little, so it won't be so cold in cotton-padded clothes, not as cold as in the north, so the weather is quite comfortable.