Find the dew point — the temperature air would need to cool to for it to become saturated and form dew — from the current air temperature and relative humidity.
How it works
Using the Magnus-Tetens approximation, air at 25°C and 60% relative humidity has a dew point of about 16.7°C. The closer the dew point is to the actual air temperature, the more humid it feels.
What this does not include
This is a widely used meteorological approximation, accurate to within about 0.4°C over typical ambient conditions — not an exact thermodynamic derivation, and it doesn’t account for altitude or unusual atmospheric pressure.
How to use this calculator
- Enter the air temperature.
- Enter the relative humidity.
Why does a high dew point feel more uncomfortable than a high temperature alone?
A dew point close to body temperature means the air is already nearly saturated, which slows evaporative cooling from sweat — the body’s main way of shedding heat, making humid heat feel far worse than dry heat at the same temperature.
What dew point is considered comfortable?
Dew points below about 60°F (15.5°C) are generally considered comfortable; above 65°F (18°C) starts to feel muggy, and above 70°F (21°C) is considered oppressive by most people.
Can the dew point ever exceed the air temperature?
No — dew point is always less than or equal to air temperature; when they’re equal, the air is at 100% relative humidity (saturated).
