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The NWS Windchill Temperature (WCT) index uses advances in science, technology, and computer modeling to provide an accurate, understandable, and useful formula for calculating the dangers from winter winds and freezing temperatures. The index:

  • Calculates wind speed at an average height of 5 feet, the typical height of an adult human face, based on readings from the national standard height of 33 feet, typical height of an anemometer
  • Is based on a human face model
  • Incorporates heat transfer theory: heat loss from the body to its surroundings, during cold and breezy/windy days
  • Lowers the calm wind threshold to 3 mph
  • Uses a consistent standard for skin tissue resistance
  • Assumes no impact from the sun, i.e., clear night sky.

Windchill Chart: Color Chart in PDF, Black and White , Knots, High Resolution TIF

Have more questions? Check our Frequently Asked Windchill Questions, Terms and Definitions page and download our free windchill brochure.

 Windchill Calculator:

Air Temperature  
Wind Speed 

Windchill Temperature:

Windchill Temperature is only defined for temperatures at or below 50°F and wind speeds above 3 mph. Bright sunshine may increase the windchill temperature by 10°F to 18°F.