Consult the Windchill Temperature Chart below to avoid severe winter conditions that could cause frostbite, hypothermia, and other hazardous health problems.
What is Windchill?
How cold it "feels" outside isn't just about temperature! You also need to consider the speed of the wind. As the wind speed increases, the body is cooled at a faster rate causing the skin temperature to drop. The combination of cold temperature and high wind could create such a severe cooling effect that your flesh would actually freeze.
How is Windchill Measured?
The windchill chart below was designed by the National Weather Service to accurately calculate how cold air feels on human skin. The index is based on heat loss from exposed skin and was tested on human subjects.
The chart also includes a frostbite indicator, showing the points where temperature, wind speed and exposure time will produce frostbite on humans. Each of the three shaded area shows how long a person can be exposed before frostbite develops. For example, a temperature of 0°F and a wind speed of 15 mph will produce a wind chill temperature of -19°F. Under these conditions, exposed skin can freeze in 30 minutes.
Dangers of Windchill
- Frostbite is body tissue that has frozen and usually starts with the fingers, toes, tips of the nose, and ear lobes. If you lose feeling in these area or they are turning pale or white, immediately get inside and get medical attention.
- Hypothermia happens when your body's temperature drops too low; uncontrollable shivering, disorientation, and incoherence are signs of this issue and medical attention should be found immediately.
In both cases, take care to rewarm the body very slowly.
Be Smart About Windchill
As well as understand the concept of windchill and what windchill temperatures mean, practice outdoor safety by:
- Listening to the weather station. Wind Chill Warnings are issued when wind chill temperatures are life threatening. Wind Chill Advisories are issued when wind chill temperatures are potentially hazardous.
- Dressing for cold weather! Wear layers of loose-fitting, warm clothing as the layers will trap air and provide insulation. Your outer shell should be water-repellent and hooded. Always wear a hat. Consider a balacalva to cover your mouth and protect your lungs. Mittens are better than gloves.
Click here to expand the chart below (PDF) .
Check out the Beaufort Wind Scale  to learn how to judge the speed of the wind!