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Dew Point Calculator

Calculate dew point temperature from humidity and temperature

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Advanced Settings (Altitude/Pressure)

Standard: 1013.25 hPa

Dew Point

12.0°C

53.6°F

Comfort Level

Dry

RH: 60%

Wet Bulb Temperature

15.0°C

59.0°F

Dew Point Spread

8.0°C

Temperature - Dew Point

Condensation Risk: Low

Low - Unlikely

Atmospheric Properties

Absolute Humidity:10.35 g/m³
Vapor Pressure:14.00 hPa
Saturation Pressure:23.33 hPa
Humidity Ratio:8.71 g/kg
Air Pressure:1013.3 hPa

Dew Point Comfort Scale

Below 10°C (50°F): Very Dry - May need humidification
10-16°C (50-60°F): Comfortable - Ideal indoor conditions
16-21°C (60-70°F): Humid - Becoming uncomfortable
Above 21°C (70°F): Very Humid - Oppressive conditions

How it works

The dew point is the temperature to which air must cool for its water vapor to start condensing — when relative humidity hits 100%. A higher dew point means more moisture in the air and a muggier feel; it's a steadier comfort gauge than humidity alone.

Dew point (approximation)

Dew point ≈ T − ( (100 − RH) ÷ 5 )   for RH above ~50%
T
air temperature (°C)
RH
relative humidity (%)

Worked example

  • Temperature = 25 °C
  • Relative humidity = 60%
  1. Dew point ≈ 25 − ((100 − 60) ÷ 5)
  2. ≈ 25 − 8

Dew point ≈ 17 °C.

Good to know

  • Comfort rule of thumb: under ~13 °C feels dry, ~16–18 °C noticeable, above ~21 °C oppressive.
  • Dew point can never exceed the air temperature; when they meet, fog or dew forms.
  • Unlike relative humidity, dew point doesn't change as the air warms or cools through the day.

Verwandte Rechner

Häufig gestellte Fragen

What is the dew point?

The temperature to which air must cool for its water vapor to begin condensing — the point where relative humidity reaches 100%. When surfaces are colder than the dew point, water condenses on them as dew, fog, or frost.

How is dew point different from relative humidity?

Relative humidity changes whenever temperature changes, even with the same moisture in the air; dew point measures the actual moisture content and stays steady through the day. That makes dew point the more reliable gauge of how muggy it feels.

What dew point feels comfortable?

Below about 13 °C (55 °F) feels dry and comfortable, 16-18 °C (60-65 °F) is noticeably humid, and above 21 °C (70 °F) feels oppressive. Summer forecasts increasingly quote dew point for exactly this reason.

How is the dew point calculated?

A handy approximation for humid air is dew point ≈ T − (100 − RH) ÷ 5, valid when RH is above about 50%. At 25 °C and 60% RH, that gives 25 − 8 = 17 °C; more precise results use the Magnus formula.

Why does dew point matter practically?

It predicts fog and frost, condensation on windows and pipes, mold risk in damp buildings, and athletic heat stress. HVAC engineers use it to size dehumidification, and painters and concrete finishers check it because coatings fail when surfaces sit near the dew point.