Dew Point Calculator

Calculate the dew point and relative humidity based on air temperature.

Dew Point Calculator

Calculate the dew point temperature (Fahrenheit).

Height (°F)

Humidity (%)

Understanding the Dew Point Calculator

Calculate the dew point temperature based on relative humidity and air temperature. The dew point indicates the temperature at which air becomes fully saturated with water vapor.

Guide

How to use the Dew Point Calculator

1Enter the current Air Temperature in Fahrenheit (°F).
2Enter the Relative Humidity (%).
3Click 'Calculate Dew Point'.
4The result shows the temperature at which dew will form.

Applications

Common Use Cases

Weather Forecasting: Predicting fog and precipitation probability.

HVAC: Managing indoor moisture levels to prevent mold.

Agriculture: Protecting crops from frost and fungal diseases.

Painting/Coating: Ensuring surfaces are dry enough for application.

The Maths Behind the Calculation

Tdp ≈ T - ((100 - RH)/5)

This simple approximation works well for high humidity (>50%). Our calculator uses the more precise Magnus-Tetens formula for all ranges.

Knowledge Base

Frequently Asked Questions

What is Dew Point?

The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%.

Is high dew point good or bad?

High dew points (above 65°F-70°F) feel very muggy and uncomfortable because sweat doesn't evaporate easily. Lower dew points feel drier and more comfortable.

Can Dew Point be higher than Air Temperature?

No, the dew point can never be higher than the air temperature. If they are equal, the humidity is 100% and it is likely raining or foggy.

Regional Notice: United States

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