Feels Like Temperature Calculator
Enter temperature, wind speed, and humidity to calculate wind chill and heat index. Know the real feels-like temperature to plan your clothing and activities.
How to Use
- Enter the current or forecasted temperature in Celsius (°C) in the Temperature field.
- Enter the wind speed in km/h in the Wind Speed field. You can get this from a weather app.
- Enter the relative humidity percentage (0-100%) in the Humidity field.
- Click "Calculate" and the system will automatically select the appropriate formula and display the feels-like temperature with comfort level.
Calculation Formulas
Wind Chill Index
WCI = 13.12 + 0.6215T - 11.37V^0.16 + 0.3965TV^0.16T = Temperature (°C), V = Wind Speed (km/h). Applicable when temp ≤ 10°C and wind > 4.8 km/h. Source: Joint Canadian/US Wind Chill Index (2001).
Heat Index
HI = -42.379 + 2.049T + 10.143R - 0.2248TR - 0.00684T² - 0.0548R² + 0.00123T²R + 0.000853TR² - 0.00000199T²R²T = Temperature (°F), R = Relative Humidity (%). Uses the Rothfusz regression equation, converting to Fahrenheit first then back to Celsius. Applicable when temp ≥ 27°C and humidity ≥ 40%. Source: US National Weather Service (NWS).
Comfort Level Chart
| Level | Feels Like Range | Suggestion |
|---|---|---|
| Extreme Cold | < -20°C | Frostbite risk, avoid going outdoors |
| Cold | -20°C to 0°C | Wear heavy warm clothing, hat and gloves |
| Cool | 0°C to 15°C | A jacket or sweater is sufficient |
| Comfortable | 15°C to 25°C | Ideal temperature for outdoor activities |
| Warm | 25°C to 32°C | Dress lightly, stay hydrated |
| Hot | 32°C to 40°C | Heat stroke risk, avoid prolonged sun exposure |
| Extreme Heat | > 40°C | Highly dangerous, avoid outdoor activities |
Calculation Examples
Example 1: Cold winter with strong wind
Conditions: Temperature -5°C, Wind 30 km/h, Humidity 70%
Calculation: WCI = 13.12 + 0.6215×(-5) - 11.37×30^0.16 + 0.3965×(-5)×30^0.16 ≈ -13.2°C
Result: Feels like approx. -13.2°C, level "Cold" — wear heavy warm clothing
Example 2: Hot summer with high humidity
Conditions: Temperature 35°C, Wind 5 km/h, Humidity 75%
Calculation: Using Rothfusz equation: convert 35°C to 95°F, apply formula ≈ 44.7°C
Result: Feels like approx. 44.7°C, level "Extreme Heat" — avoid outdoor activities
Important Notes
- Estimate only: Feels-like temperature is an estimate based on formulas. Actual perception varies by individual, affected by clothing, activity level, and physical condition.
- Formula limitations: Wind Chill applies only when temp ≤ 10°C and wind > 4.8 km/h; Heat Index applies when temp ≥ 27°C and humidity ≥ 40%. Results outside these ranges may be inaccurate.
- Sun exposure: This calculation does not account for solar radiation. Under direct sunlight, actual feels-like temperature may be 5-15°C higher than calculated.
- Wind speed source: Wind speed data should be obtained from weather services or apps. Personal perception of wind speed is often inaccurate.
- Health warning: If feels-like temperature reaches "Extreme Cold" or "Extreme Heat" levels, pay special attention to the safety of elderly, children, and those with chronic conditions.
FAQ
What is feels-like temperature and how is it different from actual temperature?
Feels-like temperature is the temperature your body actually perceives, influenced by wind speed, humidity, and sun exposure. For example, at 0°C with strong wind, it may feel like -10°C; at 35°C with high humidity, it may feel over 45°C.
Can wind chill and heat index be calculated simultaneously?
No. Wind chill applies to cold (≤ 10°C) and windy conditions, while heat index applies to hot (≥ 27°C) and humid conditions. Their applicable ranges do not overlap, and the system automatically determines which formula to use.
Why does it sometimes show 'feels-like temperature is close to actual temperature'?
When temperature is between 10°C and 27°C, or wind speed and humidity don't meet the trigger conditions, neither wind chill nor heat index applies. In such cases, the difference between feels-like and actual temperature is small.
Can the feels-like temperature result be used for medical or safety decisions?
This tool provides estimated reference values and should not be the sole basis for medical or safety decisions. In extreme weather, please refer to official warnings from your local weather service and consider your personal health condition.