Calculate the dew point temperature from air temperature and relative humidity.
Atmospheric Parameters
°C
%
Calculation Results
Enter temperature and humidity
About this calculator
Quick Reference
T_dDew Point
TAir Temperature
RHRelative Humidity
αln(RH/100) + aT/(b+T)
a, bConstants (17.625, 243.04)
Overview
The dew point is the temperature at which air must be cooled to become saturated with water vapor. When air cools below its dew point, water vapor condenses into liquid water (dew), fog, or clouds.
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Pro Tips
Dew point is always less than or equal to the actual air temperature.
A high dew point means there is more moisture in the air, which often feels 'muggy' or uncomfortable.
If the dew point is below freezing, it is typically called the frost point.
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Fun Facts
"Dew points above 21°C (70°F) are considered uncomfortable by most people."
"In the desert, the dew point can be very low, sometimes even below 0°C even when the air is hot, because the air is extremely dry."
