Why does water get cooled in an Earthen pot?
The reason why the water in an earthen pot is colder than in glass or metal vessels is: Earthen pots have numerous tiny holes in them. The water in the pot comes out through those holes and evaporates. The pot and water in it provide the necessary heat for evaporation. As a result, the earthen pot and the water in it become cold.
But a glass or metal containers do not have any holes. So there is no chance of evaporation through his body. Only a small amount of water can evaporate through the mouth of the container. So water in a glass or metal container does not get cold as much.