Why can too many clouds hinder dew formation?

Correct answer: Because clouds can reduce night-time surface cooling

Correct answer: A, because clouds can reduce night-time cooling of the surface. Dew usually forms when the ground, grass, or another surface loses heat by radiation during a clear night. As the surface cools, the air touching it may reach the dew point, and water vapour condenses into droplets. Clouds can absorb and re-emit outgoing terrestrial radiation, acting like a blanket and limiting the surface’s heat loss. The surface therefore may remain too warm for dew to form. A is correct because it identifies this cooling effect. B is wrong because clouds do not always produce frost; frost requires freezing conditions. C is clearly wrong because clouds do not turn Earth into stone. D is wrong because clouds do not remove all water vapour; they contain condensed water and may coexist with humid air. A clear, calm night is often more favourable for dew than a cloudy night. Memory cue: clear sky allows cooling; cooling helps dew.