Why is there a difference in temperature in the morning, middle and evening of a day?

The main factor is the influence of topography. Terrain will directly affect the change and direction of clouds, and clouds play a decisive role in the adjustment of ground temperature. At the same latitude, where there are thick clouds, the ground receives less solar radiation. The natural temperature is local. Clouds are thin or not, and directly exposed to the sun, the ground temperature is naturally high. The thickness of the cloud depends on the water vapor content in the cloud. Generally, clouds with sufficient water vapor come from the ocean. The overall terrain of China is high in the east and low in the west. Warm air (light) from low to high, cold air (heavy) from high to low. The meeting of cold air and warm air is the main factor of rainfall. Therefore, after the cloud reaches the mainland, it gradually rains, thus reducing the water vapor content in the cloud. The south is wet and rainy, and the northwest is dry and short of water. The northeast is full of water vapor because it is a coastal area, but the temperature is low because of its high latitude. In the south, the weather is hot and humid. Why? Generally speaking, high temperature is affected by many factors. Although it is the same latitude, the factors and conditions that affect the temperature change are different, which leads to the temperature difference.