Wind Chill Calculator
Find the wind chill, how cold it feels on exposed skin when wind adds to the cold. Enter the air temperature in °F or °C and the wind speed in mph. The calculator uses the US National Weather Service formula, which is defined at or below 50°F (10°C) and for wind above 3 mph. Outside that range it shows a note instead of a figure.
How to use the Wind Chill Calculator
- Enter your numbers in the Wind Chill Calculator above.
- Press the Calculate button to see the result.
- To try other numbers, change any value and press the button again.
The NWS wind chill formula
WC = 35.74 + 0.6215·T − 35.75·V^0.16 + 0.4275·T·V^0.16
T is the air temperature in °F and V the wind speed in mph. This is the formula on the National Weather Service wind chill page, and the NWS defines it only for temperatures at or below 50°F and wind speeds above 3 mph. In °C mode the calculator converts the temperature to °F, applies the formula and converts the answer back. The wind speed is in mph in both modes. The calculator rounds the result to one decimal.
Worked example
At 20°F with a 15 mph wind: WC = 35.74 + 12.43 − 55.14 + 13.19 ≈ 6.2°F, so 20°F feels like about 6°F. At 25 mph the calculator shows 2.6°F. The NWS page gives its own example: at 0°F and 15 mph the wind chill is −19°F, and the calculator shows −19.4°F.
Frequently asked questions
Why does wind make it feel colder?
Wind chill is based on how fast exposed skin loses heat to wind and cold. The stronger the wind, the faster it draws heat from the body, which lowers skin temperature and in time the body's internal temperature. That is how the National Weather Service describes it.
Does wind chill affect cars or pipes?
Only by cooling them faster. The National Weather Service says wind chill applies to people and animals. A car radiator or a water pipe reaches the air temperature sooner in wind, but it never cools below it. At −5°F with a wind chill of −31°F, the radiator does not drop below −5°F.
What wind chill is dangerous?
The National Weather Service gives this example: at 0°F with a 15 mph wind the wind chill is −19°F, and exposed skin can freeze in 30 minutes. Frostbite needs an air temperature below freezing, so on a day above 32°F a lower wind chill cannot cause it, though hypothermia is still possible. Local NWS offices set their own criteria for Cold Weather Advisories and Extreme Cold Warnings.
Why does the calculator show no figure at 3 mph or above 50°F?
The NWS defines wind chill only for air temperatures at or below 50°F and wind speeds above 3 mph. At 3 mph or less, or above 50°F (10°C), the calculator shows that note instead of a number.