Weather

Dew Point Calculator

Calculate dew point from temperature and humidity.

Enter the air temperature and relative humidity to calculate the dew point — a useful indicator of how muggy or comfortable the air actually feels.

Enter a valid temperature.
Enter a valid humidity (1-100%).

Dew Point

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Comfort Level

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How to Use This Tool

  1. Enter the current air temperature and relative humidity.
  2. Click Calculate for the dew point and comfort level.

The Magnus Formula

Dew point is calculated using the Magnus-Tetens approximation, which relates temperature, relative humidity, and the dew point through a logarithmic formula based on the physics of water vapor saturation.

Why Dew Point Is a Better "Mugginess" Indicator Than Humidity

Relative humidity alone is misleading because it's relative to the current temperature — 50% humidity feels very different at 60°F versus 90°F. Dew point, by contrast, is an absolute measure of moisture in the air, making it a more consistent and useful indicator of how humid the air actually feels regardless of temperature.

Dew Point Comfort Scale

Frequently Asked Questions

Why is dew point a better mugginess indicator than relative humidity?

Relative humidity is relative to the current air temperature, so the same percentage feels very different at different temperatures — dew point is an absolute measure of moisture content, making it a more reliable, consistent indicator of how muggy the air actually feels.

Can dew point ever be higher than the air temperature?

No, dew point is always less than or equal to the current air temperature — when they're equal, the air is fully saturated (100% relative humidity) and condensation (like fog or dew) can form.

This calculator is provided for general informational and estimation purposes only. Results should not be treated as professional financial, tax, legal, medical, or engineering advice. Always verify critical calculations with a qualified professional or official source before making decisions.