How is dew point calculated?

Answer 1

You need to find how much moisture is in the air in grams of water vapor per kilograms of air. We call that the mixing ratio. You then can look at what is called a skew t log p. You will also need to know what is the atmospheric pressure as well. Finally look at the chart there it is. I am sure this is better then a math equation.

Answer 2

"The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. When the dew point temperature falls below freezing it is called the frost point, instead creating frost or hoarfrost by deposition."

Answer 3

Here is a formula to calculate the dew point in degrees Celsius to within ±0.4 °C. It is valid for
0 °C < T < 60 °C
0.01 < RH < 1.0
0 °C < Td < 50 °C
where

T = temperature in degrees Celsius
RH = is the relative humidity as a fraction (not percent)
Td = the dew point temperature to be calculated

The formula is:
T_d = \frac {b\ \gamma(T,RH)} {a - \gamma(T,RH)}
where
\gamma(T,RH) = \frac {a\ T} {b+T} + \ln RH
and
a = 17.27
b = 237.7 °C
ln is the natural logarithm.

Answer 4

It's the temperature where the moisture in the air condenses on the grass or car windows or wherever it's that temperature. Any hotter, and the dew doesn't fall (or evaporates back into the air), and if it's too cold, it makes frost.

Answer 5

Look it up here:
http://en.wikipedia.org/wiki/Dew_point
I'd post the formula, but there are mathematical symbols that can't be typed in my little answer box.

Answer 6

the amount of humidity in the air

Answer 7

... or make things easy for yourself and go to the bottom of this page: http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/relhum.html