Wind Chill Calculator
Wind chill describes how cold the air feels to exposed skin when wind speed is factored in alongside the actual air temperature. When cold air moves across your skin it strips away the thin insulating layer of warm air your body generates, causing heat to escape faster than it would in still air. The colder and windier the conditions, the more severe the apparent temperature drop. The National Weather Service updated its wind chill formula in November 2001 based on clinical trials conducted in Canada. The current formula uses wind speed measured at the standard anemometer height of 33 feet (10 metres) and accounts for human face exposure at average walking speed. The formula is defined for air temperatures at or below 50°F and wind speeds of at least 3 mph. A key safety concern is frostbite: at wind chills below about -18°F, exposed skin can begin to freeze in under 30 minutes, and the risk rises sharply as temperatures fall further. The calculator below takes your temperature and wind speed inputs and computes the wind chill in both Fahrenheit and Celsius, along with an estimated time to frostbite based on the NWS frostbite chart.
Wind chill: -- °F (-- °C)
Wind chill reference table
Apparent temperature (°F) for selected air temperatures and wind speeds:
| Temp | 5 mph | 10 mph | 20 mph | 30 mph | 40 mph |
|---|---|---|---|---|---|
| 40°F | 36°F | 34°F | 30°F | 28°F | 27°F |
| 30°F | 25°F | 21°F | 17°F | 15°F | 13°F |
| 20°F | 13°F | 9°F | 4°F | 1°F | -1°F |
| 10°F | 1°F | -4°F | -9°F | -12°F | -15°F |
| 0°F | -11°F | -16°F | -22°F | -26°F | -29°F |
| -10°F | -22°F | -28°F | -35°F | -39°F | -43°F |
Source: NOAA National Weather Service.
Staying safe in wind chill conditions
When wind chill temperatures are low, exposed skin loses heat rapidly. Cover all exposed skin, wear moisture-wicking base layers, and avoid sweating excessively as wet clothing accelerates heat loss. Watch for signs of frostbite (numbness, white or grayish-yellow skin) and hypothermia (shivering, confusion, slurred speech).
Wind chill: frequently asked questions
What is wind chill?
Wind chill is the perceived decrease in air temperature felt by the body due to the flow of cold air. Wind accelerates heat loss from exposed skin by replacing the thin layer of warm air near the skin with colder air. The faster the wind, the greater the heat loss and the lower the perceived temperature.
What formula does this calculator use?
This calculator uses the NWS (National Weather Service) wind chill formula adopted in November 2001: WC = 35.74 + 0.6215*T - 35.75*V^0.16 + 0.4275*T*V^0.16, where T is the air temperature in °F and V is the wind speed in mph. The formula is valid when T is at or below 50°F and wind speed is at least 3 mph.
At what wind chill is frostbite a risk?
Frostbite can occur quickly when wind chill drops below -18°F (-28°C). At -20°F wind chill, frostbite on exposed skin can occur in 30 minutes or less. At -40°F, frostbite can occur in under 10 minutes. Frostbite time estimates are based on the NWS frostbite chart and assume light to moderate activity.
Does wind chill affect objects or only people?
Wind chill only affects living things and does not lower the temperature of inanimate objects below the actual air temperature. A car engine, water pipe, or beverage will cool to the actual air temperature but not to the wind chill temperature.
What if the temperature is above 50°F?
The NWS formula is not valid above 50°F. At higher temperatures, wind can actually feel cooling and pleasant, but the formal wind chill model does not apply. Enter a temperature at or below 50°F for a valid result.
References
- NOAA National Weather Service. "Wind Chill Chart." weather.gov
- NWS Wind Chill Temperature Index. November 2001 revision. weather.gov PDF
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.