Why does the temperature rise in the middle of the night in the north?

There may be the following reasons for the temperature rise in the middle of the night in the north:

1. Ground radiant cooling: at night, the ground heat loses less and the temperature is relatively high. Therefore, the air temperature near the ground will be gradually reduced by the influence of ground radiation, thus forming an inversion phenomenon. This inversion phenomenon is especially obvious in clear and cloudless weather.

2. Enhancement of atmospheric inverse radiation: If the clouds in the sky are thick, water vapor, carbon dioxide and other gases in the atmosphere can absorb and reflect ground radiation, thus forming inverse radiation. This kind of inverse radiation can slow down the cooling speed of the air near the ground and make the temperature rise again.

3. Humidification of the ground: After rain or in areas where water vapor is transported, the evaporation of the ground moisture will increase the water vapor content in the air. Water vapor can absorb and release heat in the air, thus affecting the temperature change. If the water vapor content in the air is high, it can absorb more heat and make the temperature rise.

4. Wind speed change: the change of wind speed will also affect the change of temperature. At night, if the wind speed is small, the heat loss in the air is slow and the temperature is relatively high; However, if the wind speed is high, the heat in the air will be lost quickly and the temperature will be relatively low.

It should be noted that these factors do not act alone, but influence and restrict each other. So in some cases, the temperature rise in the middle of the night may be a comprehensive effect.