How Is Wind Chill Calculated?

Wind chill measures what the temperature actually feels like when wind is factored in. Cold air against your skin carries heat away from your body faster than still air does — the stronger the wind, the colder it feels, even if the thermometer hasn't moved. The National Weather Service uses the following formulas to calculate wind chill.

Wind Chill (Celsius, km/h)

$$T_{chill} = 13.12 + 0.6215 T_a - 11.37 V^{0.16} + 0.3965 T_a V^{0.16}$$

\(T_{chill}\) is the wind chill temperature in Celsius, \(T_a\) is the actual air temperature, and \(V\) is the wind speed in km/h.

Wind Chill (Fahrenheit, mph)

$$T_{chill} = 35.74 + 0.6215 T_a - 35.75 V^{0.16} + 0.4275 T_a V^{0.16}$$

Same variables, but temperature in Fahrenheit and wind speed in mph.

More Information

The National Weather Service has a wind chill chart and calculator covering a range of temperatures and wind speeds.