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Dew Point

From , former About.com Guide

Dewpoint Temperature and Relative Humidity

As the temperatures drop, air becomes more and more saturated with water.

NASA Ames Research Center
Definition: Dew point temperature is the temperature at which a parcel of air must be cooled in order to reach full saturation. It is the dew point temperature which will cause dew or water droplets to form on surfaces in the mornings.

If you have ever gone outside in the summer after a hot and humid day, often the temperature will drop so low at night that the humidity in the air has no where to go except to condense onto cooler surfaces. If the temperatures drop below freezing, you get frost. Learn to calculate dew point temperature with free weather calculators.

You may also be interested in the How to Read a Hygrometer tutorial which is part of the Weather Instruments Series. A lesson plan on reading weather instruments is also available.

Also Known As: Dew point temperature, saturation temperature
Alternate Spellings: Dewpoint

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