The wind chill calculator is able to turn the subjective feeling of wind chill into an objective measurement. Most advanced weather reports now include the real temperature as well as the "wind chill temperature". If you'd like to know how to calculate wind chill yourself, read on.
How to calculate wind chill
The current formula for the wind chill calculator is as follows:
wind_chill = 13.12 + 0.6215 * air_temperature - 11.37 * wind_speed0.16 + 0.3965 * air_temperature * wind_speed0.16
The air temperature is measured in Celsius and wind speed is measured in meters per second.
What is wind chill?
You've felt the effects of wind chill if you've ever been outside on a day that is supposedly 12 degrees centigrade, yet it feels like it could be 2 degrees. It's caused by the movement of air across your skin leeching heat away from your body quicker than normal.
A surface loses heat via three primary mechanisms:
- Conduction: The transfer of energy within a "body".
- Convection: The movement of particles in liquids or gases.
- Radiation: The transmission of energy through space.
Your body naturally radiates heat all the time, warming up the air around your skin. When convection is very low, i.e. the air is still, this boundary of warmer air stays with you for longer, trapped (for a time) by the hair on your skin. The wind increases convection and blows away this boundary of warmer air, replacing it with fresh, colder air. Then, the skin will radiate more heat into the surrounding air, and body heat is conducted to the surface in order to meet this increased need.
This is the mechanism of the cooling effects of the wind. The wind chill calculator puts it into a concrete figure, which is extremely useful for practical purposes.
How can we be sure of the result?
It seems strange that a subjective experience, such as how cold a day feels, can be measured quantitatively. However, it's more than just a feeling. The reason a windy day feels colder is because more heat actually is taken away from the body. With the real-life dangers of frostbite and hypothermia it becomes very important to crack the code of wind chill and produce calculations that people can rely on.
Since not all scenarios can be predicted, wind chill calculations rely on a number of defensible assumptions and standards.
- Calculations are concerned with wind speeds at 5 feet above the ground.
- 5 feet is the typical height of an adult human face, which is the last body part we tend to cover up.
- Treats the "calm wind" threshold as 3 mph.
- Uses a standard for the conductive resistance of skin tissue.
- Assumes a clear night sky (i.e. the sun has no impact).
If you need to calculate not wind speed, but the speed of solid objects, check out our speed calculator. Have ready these two figures:
- The distance the object traveled.
- The time it took to cover that distance.
If you'd like to work in Fahrenheit, make use of our temperature conversion calculator to switch the units of the result you get from the wind chill calculator.