How is Wind Chill Calculated

There are two ways to calculate wind chill. One method is to use scientific calculations based on wind speed and outdoor temperature. The other is a reality-style method where you step outside and get slapped in the face with brutal cold, and know that there’s a mean wind chill.

For accuracy’s sake, we will work with scientific ways of calculating wind chill rather than gut instincts.

Use a Calculator

Wind chill factor is based on the heat loss rate of exposed skin caused by a combination of temperature and wind strength. As winds blow stronger, heat is lost by the body at a more rapid rate, which drives down body temperatures.

To simplify matters, a popular way to determine wind chill is to use a pre-set calculator. You can find the National Weather Service’s wind chill calculator online by clicking here. All you’ll need to enter into the calculator is the outside temperature and wind speed, and the wind chill will be figured out for you.  

Read a Chart

There’s a detailed wind chill factor chart that shows the big chill picture available on the internet. Wind speeds from calm to 60 miles-per-hour are listed on the left side of the chart, and temperatures between 40 and -45 degrees Fahrenheit are notched across the top.

The chart is also color-coded to depict wind chill levels in which a person might suffer from frostbite in five minutes, 10 minutes and 30 minutes.

Mathematical Formula

The National Weather Service’s mathematical formula presently used to calculate wind chill was established in 2001. Bearing in mind that within the formula, V represents the wind speed in miles per hour, and T represents the temperature in Fahrenheit degrees, the actual formula is:

Wind chill temperature = 35.74 + 0.6215T – 35.75V (*0.16) + 0.4275TV(*0.16)

* designates an exponent, – designates subtraction, and + designates addition. Otherwise, standard algebra rules apply.

When is the Wind Chill Dangerous?

According to, “No specific rules exist for determining when wind chill becomes dangerous. As a general rule, the threshold for potentially dangerous wind chill conditions is about -20°F.”

The National Weather Service issues official wind chill advisories and warnings when the wind chill might threaten lives if appropriate action is not taken. The criteria behind these notifications typically vary from state to state.

How to Stay Protected

After you’ve calculated the wind chill, if it appears to be potentially dangerous, here are some important facts that it’s good to know to protect yourself and your family.

* Dress warmly – Bundle yourself and children to be sure little or no skin is exposed to the elements. Use scarves to cover faces and necks, and consider wearing more than one pair of gloves to ascertain fingers are kept warm.

* Frostbite – This condition results in a loss of feeling, and a grayish tint in areas that might have been affected, such as ears, cheeks, nose, fingers or toes. Frostbite can cause permanent skin damage, and severe cases can result in amputation.

* Warming up – If frostbite is suspected, warm up frozen skin by placing against warm skin, such as placing frozen fingers an armpit to warm them up. It is important to avoid massaging, rubbing or putting heated items on possibly frozen skin because it could cause even deeper damages. If chilled skin does not return to a normal color, or if ongoing pain is suffered, seek medical attention immediately.

When dealing with cold weather, it’s better to be armed with knowledge than caught in an unpleasant situation, wondering what actions to take. Understanding how wind chill factors are calculated is a good first step to staying safe during the months where winter’s freezing wrath reigns without warmth.