The weather of the time period

Weather stations always report the highest and lowest temperatures when forecasting the weather. As we all know, it is sunny in summer, and the hottest time is not noon, but two or three o'clock in the afternoon, and the lowest temperature is early morning.

At noon, the sun shines directly on the ground. Why is the hottest time not noon?

We know that the weather is mainly determined by the temperature, and the main factor affecting the temperature is determined by the intensity of solar radiation. However, solar photothermal is not the main reason for directly raising the temperature. The total heat energy directly absorbed by air is only about 14%, and about 43% is absorbed by the ground. After the ground absorbs solar radiation heat, it undergoes radiation and convection.

When the sun shines on the ground, it heats the ground, and the heat absorbed by the ground is released to dry the air, so it takes some time for the temperature to rise after the ground is heated. After noon, when the heat released from the ground is still less than that provided by the sun, the ground temperature will not rise to the highest until two or three o'clock in the afternoon.

In the same way, after the sun went down, it lost the supply of sunlight and heat, so it began to lose heat continuously and the air flow was also decreasing. The ground temperature drops to the lowest value in the morning, so the temperature is the lowest at this time.