National Weather Service United States Department of Commerce

The wind chill temperature is how cold people and animals feel when outside. Wind chill is based on the rate of heat loss from exposed skin caused by wind and cold. As the wind increases, it draws heat from the body, driving down skin temperature and eventually the internal body temperature. Therefore, the wind makes it FEEL much colder. If the temperature is 0°F and the wind is blowing at 15 mph, the wind chill is -19°F. At this wind chill temperature, exposed skin can freeze in 30 minutes.

The NWS Wind Chill Temperature 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 does the following:

  • 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, which is the typical height of an anemometer
  • Is based on a human face model
  • Incorporates heat transfer theory based on 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.

Wind Chill converted to Knots.

Wind Chill Calculator (stays the same)

Note: The Wind Chill Temperature is defined only for temperatures at or below 50°F and wind speeds above 3 mph.

Wind Chill FAQ:

+How is the wind chill formula calculated/what is the formula?

+When are Cold Weather Advisories or Extreme Cold Warnings issued?

+Does wind chill apply only to people and animals?

+Is frostbite possible when the temperature is above freezing but the wind chill is below freezing?

+Does humidity or being near a large water body affect wind chill?

+How does this chart apply to children?

Additional information on cold-related health safety from the Centers for Disease Control and Prevention (CDC) can be found here.