Dew Point Calculator
Calculate dew point temperature from air temperature and relative humidity using Magnus formula
Calculate Dew Point
Current air temperature
Relative humidity percentage (0-100%)
Dew Point Results
Formula used: Magnus-Tetens formula with a=17.625, b=243.04°C
Input conditions: 0.0°C, 0% RH
Accuracy: ±0.35°C for temperatures from -40°C to 50°C
Input Validation
Example Calculation
Summer Day Example
Air Temperature: 24°C (75°F)
Relative Humidity: 60%
Magnus constants: a = 17.625, b = 243.04°C
Calculation Steps
1. α = ln(60/100) + (17.625 × 24)/(243.04 + 24)
2. α = -0.511 + 1.582 = 1.071
3. Dew Point = (243.04 × 1.071)/(17.625 - 1.071)
4. Dew Point = 15.6°C (60.1°F)
Dew Point Comfort Scale
Dew Point Facts
Dew point is the temperature at which air becomes saturated
Higher dew point means more moisture in the air
When temperature equals dew point, fog or dew forms
Highest recorded dew point: 35°C (95°F) in Saudi Arabia
Desert plants get ~50% of their water from dew
Understanding Dew Point
What is Dew Point?
Dew point is the temperature at which water vapor in the air begins to condense into liquid water. It's the highest possible temperature at which dew can form on surfaces. When air temperature drops to the dew point, relative humidity reaches 100% and condensation occurs.
Why is it Important?
- •Accurate measure of moisture content in air
- •Better indicator of comfort than relative humidity
- •Critical for weather forecasting and aviation
- •Essential for agriculture and HVAC systems
Magnus-Tetens Formula
Ts = (b × α) / (a - α)
α = ln(RH/100) + aT/(b+T)
- Ts: Dew point temperature (°C)
- T: Air temperature (°C)
- RH: Relative humidity (%)
- a: 17.625 (Magnus coefficient)
- b: 243.04°C (Magnus coefficient)
Accuracy: ±0.35°C for temperatures between -40°C and 50°C
Dew Point vs. Relative Humidity
Dew Point
- • Absolute measure of moisture
- • Independent of temperature
- • Better comfort indicator
- • Used in weather forecasting
Relative Humidity
- • Relative measure (percentage)
- • Temperature dependent
- • Can be misleading for comfort
- • Useful for specific applications
Dew Point Applications
🌤️ Meteorology
Weather forecasting, fog prediction, and atmospheric moisture analysis
✈️ Aviation
Carburetor icing assessment and visibility forecasting for flight safety
🌱 Agriculture
Greenhouse humidity control and plant disease prevention
🏭 Industry
Technical gas production, electronics manufacturing, and quality control
🏥 Medicine
Sterilization process monitoring and equipment validation
🏠 HVAC
Climate control systems and condensation prevention