How this wind chill calculator works
Wind chill — sometimes called the "feels-like" temperature — describes how cold the air feels on exposed skin once wind is taken into account. Your body warms a thin layer of air against your skin; wind blows that warm layer away, so heat escapes faster and the cold bites harder than the thermometer alone suggests.
This tool uses the official 2001 NWS / Environment Canada wind chill formula. In imperial units it is WC = 35.74 + 0.6215·T − 35.75·V0.16 + 0.4275·T·V0.16, where T is the air temperature in °F and V is the wind speed in mph. The metric version uses °C and km/h: WC = 13.12 + 0.6215·T − 11.37·V0.16 + 0.3965·T·V0.16.
The formula is only defined when the air temperature is at or below 50 °F (10 °C) and the wind speed is above 3 mph (about 4.8 km/h). Outside that range there is no meaningful wind-chill effect, so the calculator reports that it does not apply and simply shows the actual air temperature.
Frostbite-risk reference
The colder the wind chill, the faster exposed skin can freeze. The National Weather Service gives these approximate exposure times:
Reference note: values are wind-chill thresholds at which frostbite can occur in the stated time on exposed skin. Times are approximate and vary with individual conditions.
Frequently asked questions
- What is wind chill?
- Wind chill is the feels-like temperature on exposed skin caused by cold air combined with wind. Moving air strips away the thin layer of warmth your body builds up, so it feels colder than the thermometer reads and you lose heat faster.
- How is wind chill calculated?
- This calculator uses the 2001 NWS / Environment Canada formula. In imperial units WC = 35.74 + 0.6215·T − 35.75·V0.16 + 0.4275·T·V0.16, where T is air temperature in °F and V is wind speed in mph. The metric version uses °C and km/h with its own coefficients.
- At what wind chill is frostbite a risk?
- Frostbite can occur in about 30 minutes when the wind chill falls to roughly −19 °F (−28 °C), in about 10 minutes near −35 °F (−37 °C), and in about 5 minutes near −60 °F (−51 °C). The colder the wind chill, the faster exposed skin freezes.
- Does wind chill affect objects or cars?
- No. Wind chill only describes how cold it feels to people and animals that generate body heat. Wind can make a car, pipe or other object reach the actual air temperature faster, but it cannot cool an object below the true air temperature.
- What is the difference between wind chill and the actual temperature?
- The actual temperature is what a thermometer measures. The wind chill is an index of how cold that temperature feels once wind is factored in. Wind chill is always equal to or lower than the actual temperature, never higher.
- What conditions does wind chill apply to?
- The standard formula applies when the air temperature is at or below 50 °F (10 °C) and the wind speed is above 3 mph (about 4.8 km/h). Outside that range wind chill is not defined and the feels-like temperature is taken as the actual air temperature.