Feels Like Temperature Calculator
Enter the temperature, humidity, and wind speed to see how hot or cold it really feels.
Calculated in °C using the NWS heat index and wind chill formulas.
What is the "feels like" temperature?
The feels like temperature, also called the apparent temperature, is how hot or cold the air actually feels to your body once humidity and wind are taken into account. The thermometer reading alone does not tell the whole story: high humidity makes a hot day feel even hotter because sweat evaporates more slowly, while wind on a cold day strips heat from your skin and makes it feel colder.
This calculator works in degrees Celsius. When it is hot (27°C or above) and humid, it applies the US National Weather Service heat index (the Rothfusz regression). When it is cold (10°C or below) and the wind is above 4.8 km/h, it applies the NWS wind chill formula. In mild conditions in between, the air simply feels like the actual temperature, so that is what is shown.
How to use it
Enter the air temperature in °C, the relative humidity as a percentage, and the wind speed in km/h. The result updates instantly and tells you both the feels like temperature and which model was used: heat index, wind chill, or the actual temperature. Everything runs in your browser, so no data is sent anywhere.
FAQ
Why is the feels like temperature different from the thermometer? Your body loses heat through sweat and convection. Humidity slows sweat evaporation so heat feels worse, while wind speeds up heat loss so cold feels worse. The apparent temperature blends these effects into a single number.
When is heat index used instead of wind chill? Heat index applies on hot, humid days (about 27°C and warmer). Wind chill applies on cold, windy days (about 10°C and colder with wind above 4.8 km/h). Between those ranges, the feels like value equals the actual temperature.
Why does humidity barely change the result on a cool day? The heat index only meaningfully raises the apparent temperature when it is already warm. In cool weather humidity has little effect, so the calculator reports the actual temperature instead.
Which formulas does this use? The heat index uses the NWS Rothfusz regression with the standard low- and high-humidity adjustments, and the wind chill uses the NWS metric wind chill formula. Both are widely used by national weather agencies.