What Is Wind Chill?
When a winter forecast feels far colder than the thermometer reading, wind is almost always the reason. The stronger the wind, the faster heat is stripped from exposed skin, cooling your body faster than still air would. This effect is quantified as wind chill, and this calculator applies the formula automatically whenever temperature is 10°C or below and wind speed is at least 4.8 km/h.
The Wind Chill Formula
This calculator uses the formula jointly adopted by the US National Weather Service and Environment Canada in 2001.
Formula: Wind Chill = 13.12 + 0.6215T − 11.37V^0.16 + 0.3965T × V^0.16
Here, T is air temperature in °C and V is wind speed in km/h. As an example, at -10°C with a 30 km/h wind, the feels-like temperature drops to about -20°C — a 10-degree swing that meaningfully changes frostbite risk timelines.
Winter Safety Tips
For hiking, skiing, or a cold commute, check the feels-like temperature, not just the air temperature. Once it drops to -25°C or below, frostbite risk on exposed skin rises sharply, so proper cold-weather gear is essential.
Looking for summer humidity-based heat index instead? Check the year-round feels-like temperature calculator.
Frequently Asked Questions
- Does wind chill apply if wind speed is under 4.8 km/h?
- No — the formula only applies at 4.8 km/h or above. Below that, or above 10°C, the calculator simply shows the actual air temperature.
- At what feels-like temperature should I worry about frostbite?
- Frostbite risk begins around -15°C feels-like temperature with prolonged exposure, and can occur within 30 minutes at -25°C or below — take extra precautions at that point.