What is the windchill factor?

Answer 1

The wind-chill factor is a method for accounting for the effect of wind speed which affects the rate of heat loss of the human body. In cold, still air, we continually lose body heat at a rate depending on the temperature difference between the skin and the air, and the amount of insulation - like clothing - we're wearing. When the skin loses heat, it will cool to somewhere below 37 C. The colder the air, the greater the heat loss and the skin cooling. When the wind picks up speed it will carry away the warmish air layers immediately next to our skin and in our insulating clothing. The skin temperature is further decreased and we interpret that as our being in a colder environment. The greater the wind speed, the greater loss of that warmed air layer next to our body. There are two different ways, one used by the Australians and Europeans, another used by The USA and Canada. You can follow the links for more details. Both provide the actual formula for calculating the wind chill factor. The NOAA link has interactive charts.

Answer 2

Its a method used by weather forecasters how much coder the wind makes unclothed skin feel