"When we first introduced AccuWeather RealFeel® Temperature, we knew we had invented something special that would become an industry standard," Dr. Joel N. Myers, founder and president of AccuWeather, said. "Now users have access to forecasts of the RealFeel Temperature wherever they go, making it part of their regular routine and helping them decide whether they need coats, sweaters or scarves."

Pedestrians walk along a snow-covered sidewalk, Saturday Dec. 17, 2016, in Brooklyn, N.Y. (AP Photo/Bebeto Matthews)

First established in the 1990s by Dr. Joel N. Myers, AccuWeather Chief Meteorologist Elliot Abrams, Chief Operating Officer and Expert Meteorologist Evan Myers as well as Michael A. Steinberg and Dr. Joseph Sobel, the patented AccuWeather RealFeel® Temperature was created to determine how the outside temperature is perceived by the average person.

“The RealFeel Temperature is supposed to give people a sense as to what the temperature feels like,” said AccuWeather Senior Meteorologist Dan Kottlowski. “What we are trying to do is determine how much weather variables alter the feeling of the temperature upon our skin.”

The index is made up of seven different weather variables: temperature, dew point/humidity, wind, precipitation, visibility, cloud cover/UV index and the sun angle. Each factor individually affects whether the air will feel cooler or warmer than what the actual temperature reads.

AccuWeather is the only company to use more than two variables to calculate a “feels like” temperature.

In the winter, especially, these factors are something to consider when determining how to bundle up.

On some days, sub-freezing temperatures could be predicted but a lack of certain factors and an increase in others may cause the air to feel warmer. On other days, different factors can cause sub-freezing air temperatures to feel more than 10 degrees Fahrenheit lower than what thermometers register.

Direct sunshine with no wind and low humidity can create the highest RealFeel Temperatures, Kottlowski said.

“The more humid it is outside, the warmer it feels, even in the winter without the wind. This is particularly true when the sun is shining,” Kottlowski said. “A combination of sunshine, high humidity and no wind makes for the highest RealFeel values with respect to the temperature.”

On the other hand, evaporational cooling, wind, precipitation and thick clouds can cause temperatures to feel lower than what is recorded.

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“When evaporation takes place, the temperature lowers because heat is required to cause the evaporation process,” Kottlowski explained. “The reduction of heat leads to a lower temperature, so a combination of wind and precipitation would lower the temperature on the skin the most.”

As the first and leading source of temperature impact forecasts, the RealFeel Temperature is available across all digital devices from the AccuWeather.com web and mobile web sites to apps on every major mobile platform. You can find the RealFeel Temperature on your local forecast page on AccuWeather.com. It's also included in AccuWeather's exclusive 90-day forecast.

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For more safety and preparedness tips, visit AccuWeather.com/Ready.