Dew Point
The dew point is the temperature to which air must be cooled, at constant barometric pressure, for water vapor to condense into water. The condensed water is called dew. When the dew point temperature falls below freezing it is called the frost point, as the water no longer creates dew but instead creates frost. The dew point is associated with relative humidity. A high relative humidity indicates that the dew point is closer to the current air temperature. If the relative humidity is 100%, the dew point is equal to the current temperature. Given a constant dew point, an increase in temperature will lead to a decrease in relative humidity.