Dew Point Calculator
Calculate the dew point from air temperature and relative humidity. The dew point is the temperature at which water vapor condenses into liquid.
Calculates the dew point temperature from air temperature and relative humidity.
How It Works & Formula
The Magnus formula approximates the dew point: alpha = (a x T)/(b + T) + ln(RH/100) and Td = (b x alpha)/(a - alpha), with a = 17.27 and b = 237.7.
Frequently Asked Questions
What is the dew point?
The dew point is the temperature to which air must cool for water vapor to condense into dew or fog.
What is a comfortable dew point?
Dew points below 15 degrees Celsius feel comfortable, while above 20 degrees Celsius feels humid and muggy.
How is dew point different from humidity?
Relative humidity depends on temperature, while dew point is an absolute measure of moisture in the air.