Dew point (original) (raw)

The Dew point of a given parcel of air is the temperature to which the parcel must be cooled, keeping pressure constant, for it to become saturated with water vapor. At this temperature condensation will begin if conditions are suitable (presence of a solid surface or other condensation nuclei; otherwise see supersaturation) — water vapor then condenses into liquid water called dew. When the dew point temperature falls below freezing it is called the frost point.