Why is there dew on grass and other objects outside in the morning?

Question

My friends and I were having a conversation on this topic the other and wanted to know the facts. Thanks.

Answer 1

During the day, the air is hotter because of sunlight heating things up.  Hot air can hold more moisture in a vapourous state than cold air, so when the sun goes down - the heating stops too and so the air and surroundings gradually cool and as it does so, some of the water held in suspension is deposited onto cool surfaces as it transitions back to being a liquid - condensation.

Answer 2

Once the sun goes down, radiational cooling begins. Heat is emitted from Earth's surface, and the surface cools down because of it. The moisture in the air will condense if the air temperature is cooled to the dew point. The dew point is the temperature to which air must cooled for saturation to occur. When 100% relative humidity is achieved, water vapor condenses around blades of grass and other stuff to form dew.