Wind Chill Calculator

Wind chill is the perceived temperature on exposed human skin when cold air and wind combine. Moving air strips away the thin warm layer that insulates your skin, making the air feel colder than a thermometer reads. A 30 °F day with 20 mph wind, for example, feels like 17 °F.

It uses the 2001 NWS formula: WC (°F) = 35.74 + 0.6215 x T - 35.75 x V^0.16 + 0.4275 x T x V^0.16, where T is air temperature in °F and V is wind speed in mph. The NWS defines this formula only for temperatures at or below 50 °F and wind speeds at or above 3 mph. Outside that range, the calculator returns the measured air temperature rather than extrapolating the formula.

For valid cold-weather inputs, the calculator marks risk as increasing at wind chill values of -19 °F or lower, high at -33 °F or lower, and severe at -48 °F or lower. Its time labels are 30, 10, and 5 minutes respectively. Actual frostbite risk depends on temperature, wind, clothing, wetness, and exposed skin, so use the result as a caution, not a safety guarantee.

No. Wind chill is defined only for living skin, which generates heat. Inanimate objects like pipes, car engines, or your windshield cool only down to the actual air temperature, never below it. Wind does speed up how fast they reach that temperature, but they cannot get colder than the surrounding air.

The NWS formula is defined only for temperatures at or below 50 °F and wind speeds at or above 3 mph. The calculator warns when the air is warmer than 50 °F or the wind is above 0 but below 3 mph. At 0 mph, it simply returns the air temperature.