Calculate the apparent temperature from wind chill or heat index.
Calculated locally in your browser.
How is the feels-like temperature calculated?
Wind chill (≤10°C) uses the Environment Canada/NWS formula with temperature and wind speed, while heat index (≥27°C) uses the NWS Rothfusz regression with temperature and humidity. For example, −5°C with a 20 km/h wind feels like about −11°C, and 32°C with 70% humidity feels much hotter than the thermometer reads.
Understanding your result
Wind chill matters in the cold (wind strips body heat); heat index matters in the heat (humidity slows sweat evaporation). In mild conditions it feels close to the actual temperature.
Formula and method
Wind chill (≤10°C) uses the Environment Canada/NWS formula with temperature and wind speed. Heat index (≥27°C) uses the NWS Rothfusz regression with temperature and humidity.
Assumptions and limitations
It applies the wind chill formula in cold conditions and the heat index in hot, humid ones, so it needs wind speed for the cold and humidity for the heat. In mild weather the feels-like value stays close to the actual temperature, and these are standard estimates, not a personal measurement of comfort.
Worked example
At −5°C with a 20 km/h wind it feels like about −11°C; at 32°C with 70% humidity it feels much hotter than the thermometer reads.
How to use this tool
- Choose metric or imperial units.
- Enter the temperature, wind speed and humidity.
- Press Calculate.
About the Feels-Like Temperature Calculator
The Feels-Like Temperature Calculator shows how cold or hot it actually feels by applying the wind chill formula in cold weather and the heat index in hot, humid weather.
Who should use this tool
People planning outdoor activity in extreme weather, runners and cyclists deciding what to wear, parents judging conditions for children, and anyone who wants the apparent temperature that combines wind chill in the cold or humidity in the heat with the thermometer reading.
Benefits
- Applies wind chill in the cold and heat index in the heat
- Uses established meteorological formulas for the apparent temperature
- Helps you dress appropriately for genuinely extreme conditions
- Runs free in the browser with no sign-up
Practical use cases
- Deciding how warmly to dress on a windy winter day
- Judging whether it is too hot and humid to exercise
- Planning safe outdoor time for children in extreme weather
- Understanding why a still day feels warmer than a windy one
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Frequently asked questions
Which formula does it use?
It picks automatically: wind chill when it’s cold and windy, heat index when it’s hot and humid, otherwise the actual temperature.
Why does wind make cold weather feel colder?
Wind strips away the thin layer of warm air your body heats around your skin, so heat escapes faster and you feel colder than the thermometer reads. That is why the wind chill formula combines temperature and wind speed. At minus 5 degrees with a 20 km/h wind it can feel like about minus 11.
Why does humidity make hot weather feel hotter?
Your body cools itself as sweat evaporates. When the air is already very humid, sweat evaporates far more slowly, so cooling is reduced and it feels hotter than the actual temperature. The heat index captures this, which is why 32 degrees at 70% humidity feels considerably worse.