Wind Chill Calculations
Wind Chill is the apparent temperature felt on the exposed human body owing to the combination of temperature and wind speed.
From 1945 to 2001, Wind Chill was calculated by the Siple and Passel Index. In our calculator, this is labeled as the "Old Wind Chill."
Starting with the 2001/2002 winter season the NWS started calculating Wind Chill with an improved formula called the Wind Chill Temperature (WCT) index. In our calculator, this is labled as the "New Wind Chill."
