Does the “Wind Chill Index” correctly indicate how cold it feels?
Not exactly. The Wind Chill Index (WCI) is designed to tell you how cold you should feel, based solely on the current wind speed and air temperature. For example, if the current temperature is -22°F (-30°C), and the wind speed is 35 mph (15.6 m/s or 56 km/h), the WCI is equivalent to -58°F (-50°C). This is supposed to be the equivalent of walking at 3 mph (1.3 m/s or 4.8 km/h) in calm air at the WCI temperature. Several variables that affect how you really feel were approximated and incorporated into the formula as constants. Such things as surface wind speeds that vary significantly from the official measurements (usually due to sheltering effects of trees and buildings), skin that is already cold, and wind-breaking effects of certain clothing articles can cause the “real” wind chill to differ from the WCI. Still, the WCI is a reasonable approximation. Note that the above discussion has been updated (Dec.
