Wind Chill Calculator
Calculate the feels-like temperature based on air temperature and wind speed.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Wind chill tells you how cold it actually feels on exposed skin when you factor in wind speed. This is critical for planning outdoor activities in cold weather and avoiding frostbite. Here is how to use the calculator:
- Enter the air temperature. Use the actual reading from a thermometer in degrees Fahrenheit. Wind chill is only meaningful when the temperature is 50°F or below. Above 50°F, wind does not produce a significant chilling effect on skin.
- Enter the wind speed. Use the sustained wind speed in miles per hour. You can find this from a local weather report, weather app, or anemometer. The wind chill effect becomes noticeable at wind speeds of 3 mph or higher. At calm winds, the feels-like temperature equals the actual temperature.
Results update instantly. The primary result shows the wind chill temperature in Fahrenheit. The breakdown section shows the danger category, frostbite risk level, and the Celsius equivalent. The danger categories are based on the National Weather Service wind chill chart and range from "Low Risk" to "Extreme Danger" depending on how quickly frostbite can develop on exposed skin.
Use the Share button to send conditions to friends or family before an outdoor trip, or Copy to save the result. All calculations use the NWS wind chill formula and run entirely in your browser.
About Wind Chill
Wind chill is a measure of how cold the air feels on exposed skin. When wind blows across your skin, it removes the thin layer of warm air your body generates, making you lose heat faster. The result is that your skin cools to a lower temperature than what the thermometer reads. The current wind chill formula was adopted by the National Weather Service and Environment Canada in 2001 and is based on a model of heat loss from the human face.
The formula is: Wind Chill = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16), where T is air temperature in Fahrenheit and V is wind speed in mph. This formula is valid for temperatures at or below 50°F and wind speeds above 3 mph.
Frequently Asked Questions
What is wind chill?
Wind chill is a calculated temperature that describes how cold the air feels on exposed skin when wind is factored in. It is not the actual air temperature but rather a measure of the rate of heat loss from your body. For example, an air temperature of 25°F with a 15 mph wind produces a wind chill of about 13°F. Your skin loses heat at the same rate as it would in calm air at 13°F. Wind chill does not affect objects like pipes or car engines, which can only cool to the actual air temperature.
How is wind chill calculated?
The National Weather Service uses the formula: Wind Chill = 35.74 + 0.6215T - 35.75(V^0.16) + 0.4275T(V^0.16), where T is the air temperature in Fahrenheit and V is the wind speed in mph. This formula was developed in 2001 based on clinical trials that measured heat loss from the human face in controlled wind conditions. It replaced an older formula from the 1940s that tended to overestimate the chilling effect.
At what wind chill is it dangerous to go outside?
The National Weather Service issues a Wind Chill Advisory when values fall between -15°F and -24°F, and a Wind Chill Warning at -25°F or below. At -20°F wind chill, frostbite can develop on exposed skin in about 30 minutes. At -35°F, frostbite can occur in as little as 10 minutes. At -50°F or below, frostbite can develop within 5 minutes. Always cover exposed skin, wear layers, and limit time outdoors in extreme cold.
Is wind chill the same as the actual temperature?
No. Wind chill is a perceived temperature that applies only to human skin and other warm-blooded animals. The actual air temperature remains the same regardless of wind speed. A car engine, water pipe, or any inanimate object will cool to the actual air temperature, not the wind chill temperature. However, wind does increase the rate at which objects cool, meaning they reach the actual air temperature faster. Wind chill is a useful safety metric for people, but for pipes and equipment, use the actual thermometer reading.