Why is it hot in summer?

Because China is located in the northern hemisphere, and most areas are located in the northern temperate zone.

Temperate areas are warm in winter and cool in summer.

China is influenced by the trade winds except Kunming, and the seasons are like spring; Guangdong, Hong Kong, Macao and Taiwan are located in the tropics, and other places are temperate except for the hot season.

Moreover, the height angle of the sun is the largest in summer, and the sun shines almost directly on the earth. Solar energy reaches the earth with the most heat, and the earth gets more energy from the sun, so it is hot in summer.

Because the revolution of the earth around the sun is an ellipse, in winter, our earth just rotates to the apohelion, far from the sun, and gets less heat. In summer, the earth just rotates to the perihelion and is close to the sun, so it must get more heat.

So it's normal to be warm in the east and cool in summer.

The so-called calm, naturally cool, don't warm yourself up.