Enter the temperature and relative humidity into the calculator to determine the dew point. The dew point is the temperature at which air becomes saturated with moisture and fog is likely to form.
Fog Equation (Dew Point Formula)
The following formula is used to calculate the dew point temperature:
DP = (b * α) / (a - α)
where:
- DP is the dew point temperature (°C)
- α is a function of temperature (T) and relative humidity (RH), given by α = (a * T / (b + T)) + ln(RH / 100)
- a = 17.27 and b = 237.7 are constants for the Magnus-Tetens approximation
To calculate the dew point, input the current temperature and relative humidity into the formula to solve for the dew point temperature. This value indicates the temperature at which the air can no longer hold all of its water vapor, and some of the water vapor must condense into liquid water, forming fog.
What is Dew Point?
The dew point is the temperature at which air reaches its saturation point and water vapor in the air begins to condense into liquid water. This is a key concept in meteorology and is used to predict the formation of dew, frost, and fog. A higher dew point indicates more moisture in the air, which can lead to a greater likelihood of rain and foggy conditions.
How to Calculate Dew Point?
The following steps outline how to calculate the Dew Point.
- First, determine the current temperature (T) in degrees Celsius.
- Next, determine the relative humidity (RH) as a percentage.
- Use the Magnus-Tetens approximation to calculate α: α = (a * T / (b + T)) + ln(RH / 100).
- Finally, calculate the Dew Point (DP) using the formula: DP = (b * α) / (a – α).
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Temperature (T) = 15°C
Relative Humidity (RH) = 80%
