Wind Chill Calculator

The NWS Wind Chill Formula

This calculator uses the official National Weather Service wind chill formula, adopted in 2001 by the US and Canada: WCT = 35.74 + 0.6215T − 35.75(V^0.16) + 0.4275T(V^0.16), where T is the air temperature in °F and V is the wind speed in mph. The formula is only valid for air temperatures at or below 50°F and wind speeds of 3 mph or greater — outside that range, wind has little meaningful cooling effect on exposed skin, so the calculator simply reports the actual air temperature instead of an extrapolated (and misleading) wind chill value.

Why Wind Chill Feels Colder Than the Thermometer

Wind strips away the thin layer of warm air your body naturally holds against your skin, speeding up heat loss and making the air feel colder than its actual temperature. The effect grows quickly at first as wind speed increases from calm, then levels off — going from 5 mph to 15 mph makes a much bigger difference than going from 35 mph to 45 mph, which is why the formula uses wind speed raised to the 0.16 power rather than a straight linear relationship.

A Common Misconception

Wind chill describes how cold exposed skin feels and how fast it loses heat — it does not describe the temperature that water, car engines, or other objects will actually cool to, since those aren't warmed by metabolism the way skin is. A pipe or windshield will still cool toward the actual air temperature, not the wind chill value. For related outdoor-planning math, see the heat index calculator for the summertime equivalent, or the dew point calculator to gauge how damp the air feels.