Question

why is it warmer on a wintry night when clouds cover the sky than when it is clear

Answer 1

At night cloud cover has the opposite effect. If skies are clear, heat emitted from the earth's surface freely escapes into space, resulting in colder temperatures. ... As a result, temperatures decrease more slowly than if the skies were clear.

Answer 2

this is coz during such nights the clouds so not the radiations of the earth escape into the atmosphere.