Why is it not cold in winter in Hong Kong?

Hong Kong has a subtropical climate because it is not cold in winter. The annual average temperature is not low, reaching 22.8 degrees. In winter in Hong Kong (from mid-February of 65438 to late February of the following year), the temperature is between 14 and 20 degrees Celsius, the average temperature is 17 degrees, and the humidity is about 72%. When the weather is cool, you should wear a suit and a thin sweater. When the temperature occasionally drops to 10 degrees Celsius, you need to wear a coat.