💧 Dew Point Calculator
Enter the temperature and humidity to get the dew point — the truest measure of how humid and muggy it feels.
Dew point
60.2°F
15.7°C
How it feels
Pleasant
The dew point is the temperature at which air becomes saturated and dew forms — a better measure of "muggy" than humidity alone. Computed with the Magnus formula (Alduchov–Eskridge coefficients). Above about 18°C (65°F) it starts to feel sticky; above 24°C (75°F) is oppressive. 🔒 In your browser.
How the dew point calculator works
The dew point is the temperature to which air must cool for water vapour to start condensing — dew, fog or clouds. The tool computes it from the temperature and relative humidity with the Magnus formula (Alduchov–Eskridge coefficients). Unlike relative humidity, the dew point maps directly to comfort, so it's what meteorologists watch for muggy conditions.
A dew point below 55°F (13°C) feels comfortable and dry; 60–65°F (16–18°C) starts to feel sticky; above 70°F (21°C) is oppressive and above 75°F (24°C) can be dangerous. It also tells you the overnight low can rarely fall below the dew point.
Frequently asked questions
What is the dew point?
The temperature at which air becomes fully saturated and water vapour condenses into dew, fog or cloud. It's a direct measure of how much moisture is in the air — and how muggy it feels.
How is dew point calculated?
From temperature and relative humidity using the Magnus formula. This tool uses the Alduchov–Eskridge coefficients (a = 17.625, b = 243.04) for accuracy across normal weather temperatures.
Is dew point better than humidity for comfort?
Yes. Relative humidity depends on temperature and can be misleading; the dew point is an absolute measure. A 70°F dew point feels muggy whether the air temperature is 75°F or 95°F.
What dew point feels comfortable?
Below about 55°F (13°C) feels pleasant and dry; 60–65°F is noticeably humid; above 70°F (21°C) is oppressive. Many people find a dew point around 50–55°F ideal.
Can the dew point be higher than the temperature?
No — the dew point can equal the air temperature (that's 100% humidity, saturation) but never exceed it. If they're equal, expect fog or dew.
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From the blog
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Dew Point vs Relative Humidity: Why 100% Humidity Can Feel Fine and 50% Can Feel Awful
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VPD — vapor pressure deficit — is the single number serious growers tune instead of humidity, because it accounts for temperature. Here's what it means, how it's calculated, and the target VPD ranges for each growth stage.