Why is it so hot in Guangzhou?

First of all, geographically, Guangzhou is located in the Tropic of Cancer and belongs to the subtropical monsoon climate. Affected by the Pacific high (Hawaii high), Guangzhou is at a relatively low pressure, so sometimes it rains heavily, and sometimes the sun shines high. However, from the perspective of the city, Guangzhou is a mega-city with a population of100000, which will produce the heat island effect. Besides, the cars are all working, so it's not hot. Finally, this year, due to the influence of La Nina phenomenon (anti-El Ni? o phenomenon), whether it is hot or cold, it will be extreme. Pay attention to prevent heatstroke. Today is a big summer, let's go swimming.