Why is it sunny in summer in northern China and the temperature rises rapidly? Explain in detail respectively

The reason for the rapid temperature rise is related to the specific heat.

There are few rivers in the north, and the altitude in the south is relatively high.

For example, the north is regarded as a dry soil area and the south as a wet soil area.

Dry soil is heated quickly by the same intensity of sunlight, but the temperature drops immediately without sunlight (dry soil has high specific heat capacity).

The wet soil area is full of heat (small specific heat capacity) under the same sunshine, but the temperature drops slowly when there is no sunshine.

This is the rapid heat in the north. One reason for being cold is also being fast.