Wind Chill Calculator
Enter the air temperature and the wind speed. You get the wind chill temperature and how many degrees colder it feels than the air.
Your numbers
How we calculate it
The wind chill index is a formula fitted to how fast skin loses heat in wind. In the US National Weather Service version (2001), with the temperature T in °F and the wind speed V in mph, it is 35.74 + 0.6215 T − 35.75 V^0.16 + 0.4275 T V^0.16. The Canadian version, with T in °C and V in km/h, is 13.12 + 0.6215 T − 11.37 V^0.16 + 0.3965 T V^0.16. They are the same model in different units.
For example, at 30 °F with a 15 mph wind the wind chill is 19 °F. At −10 °C with a 20 km/h wind it is −17.9 °C, which Environment Canada rounds to −18.
Assumptions and limits
- Weather figures are estimates for general information. Check your local weather service for warnings and advice.
- The formula is only defined for temperatures at or below 50 °F (10 °C) and winds of at least 3 mph (4.8 km/h). Outside that range the calculator says so.
- Wind chill describes the effect on exposed skin. It does not change the real temperature of objects such as a car or a pipe, and sun and clothing change how it feels.
Frequently asked questions
What is wind chill?
It is a measure of how cold the air feels on bare skin when the wind is blowing. Wind carries heat away from the body faster, so the same temperature feels colder.
Does wind chill change the actual temperature?
No. Water in a bucket will not freeze below the air temperature because of wind chill. It only describes the cooling of people and animals.
What is the wind chill at 30 °F and 15 mph?
It is 19 °F (about −7 °C). The calculator shows the answer and the number of degrees it feels colder than the air.
Related calculators
Worked example (a fixed example using the starting numbers, it does not change as you type)
Inputs: Units = US (°F and mph); Air temperature (°F) = 30; Wind speed (mph) = 15.
- Wind chill 19.0 °F
- Temperature difference -11.0 °F
- Also in °C -7.2 °C
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