The reason at night, it is warmer when it is cloudy

Clouds act as shields, preventing heat from passing through the atmosphere into the atmosphere.

Why at night, is it warmer when it is cloudy?

The cloud acts like a shield to prevent heat from escaping into space.

During the day, our Earth receives light from the Sun and is warmed. When night falls, if the sky is clear, ie there is no cloud, the heat easily passes through the atmosphere, entering space. Therefore, the Earth is cooled.

Now, to understand what happens on a cloudy night, let's warm up the Earth again.

In this case, the clouds act like a shield to prevent heat from escaping into space. Because the heat is kept in the atmosphere, the cloudy night will be warmer than the clear night.