Dew Point Calculator

Air Temperature Temperature
Fahrenheit Celsius

Relative Humidity Relative Humidity (%)

Settings Show step-by-step derivation
Magnus constant a
Magnus constant b (degrees C)

The default a = 17.27, b = 237.7 is specified for 0 to 60 degrees C (about 0.4 degrees C accuracy). The Alduchov-Eskridge set a = 17.625, b = 243.04 covers -40 to 50 degrees C.

Dew Point:

Comfort Level:

Note: The dew point is below freezing. Frost formation is likely on exposed surfaces.

Step-by-Step Derivation