Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page Visit Our Archives Ask A Question How To Ask A Question Question of the Week NEWTON Teachers Our Expert Scientists Volunteer at NEWTON! Referencing NEWTON Frequently Asked Questions About Ask A Scientist About NEWTON Education At Argonne Occluded Fronts and Dew Points

Name: Teagan
Status: student
Grade: 6-8
Location: MI
Country: USA
Date: Summer 2012

Ok, so my question has to do with relative humidity and the dew point. I understand that the dew point is the point at which condensation starts to form on a solid object when the temperature drops to or below it, and I understand that humidity is the amount of moisture in the air at any given temperature. What I would like to know is why, during a occluded front to be specific, the dew point drops. From the notes I've gathered, it would seem that the temperature stays the same during an occluded front and I'm just not sure if that effects the dew point or not. Does the temperature have nothing to do with the dew point dropping? Did I get the wrong information? Or am I misinterpreting the ideas behind dew point, occluded fronts, and temperature?

The dew point is an indirect measure of the amount of water in the air. Much water in the air (it is humid and clammy), and the dew point is near the present temperature. If the dew point drops that says there is less moisture in the air - it is direr.

So, when the front passes, new, drier air is brought into the area and the dew point drops.

To directly answer your question, the actual temperature of the air and the dew point do not tell us much about the humidity of the air, BUT the difference between the two temperatures tells us a lot.

Hope this helps.

Bob Avakian Oklahoma State University Institute of Technology

Click here to return to the Weather Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 223
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: November 2011
Weclome To Newton

Argonne National Laboratory