Why is the temperature difference between day and night smaller on cloudy days?

It is cloudy in the country and cloudy in the sky, which plays a role in heat preservation.

During the day, heat mainly comes from the sun, but at night, it mainly comes from the thermal radiation of Mother Earth.

If there is no cloud weather, heat will radiate outside the atmosphere, and if there is cloud weather, it can refract heat radiation and play a role in keeping warm.

I hope the landlord is satisfied with this answer.