Why is there fog in the morning?

The main reasons for fog in the morning are as follows:

1. The temperature difference between day and night is large, which causes the water vapor in the air to condense into fog. At night, the ground heat dissipates quickly, and the ground temperature drops sharply, so that the temperature near the ground also drops. When the temperature drops to a certain extent, the water vapor in the air will condense into fog. At the same time, if there is enough water vapor in the air, the temperature drop at night will lead to more obvious condensation of water vapor.

2. The increase of wind speed helps to disperse the fog. In the early morning, due to the low ground temperature and high air density, a downward airflow was formed. With the passage of time, the ground temperature gradually increases, the air density decreases, and the wind speed increases, which helps the fog to dissipate.

3. The air convection is weak, which is not conducive to the formation of fog. During the day, the sun shines on the ground, the ground temperature rises, and the air convection movement increases, which is not conducive to the formation of fog. At night, the ground temperature drops, and the air convection motion weakens, which is beneficial to the formation of fog.

To sum up, the main causes of fog in the early morning are large temperature difference between day and night, increased wind speed and weak air convection.