As air rises it cools due to expansion which increases the relative humidity. As you learned, the relative humidity depends on the air temperature and dew point temperature. You can explore the relationship between the dew point and temperature near the ground and the altitude at which a cloud will form.

The Verner E. Suomi Virtual Museum development funded in part by the National Science Foundation Grant #EAR9809458.  Material presented is Copyrighted (C) 1999 by Steve Ackerman and Tom Whittaker.  If you have questions or comments, please let us know!