In this lastest stink of cold weather, I got to thinking about what wind chill really means and how it affects our outlook on the weather. The above chart is caculated using NOAA's National Weather Services equation.
Here is how you calculate the Wind Chill Index:
Wind Chill T(wc) = 35.74 + 0.6215T - 35.75(V0.16) + 0.4275T(V0.16)
where T(wc) is the Wind Chill in degrees F, V is the Wind Speed in MPH, and T is the temperature in degrees F.
On these cold winter days a breeze makes the cold feel more uncomfortable as it drives heat away form the exposed skin faster than calm air. This might be a good week to have your students caculate the wind chill and gain an understanding that without a hat they may truely be at risk of frostbite in as little as 5 minutes - say that mad dash to the car.
A great book with wind chill descriptions from real life (middle school level) The Children's Blizzard by
Here is a NPR podcast on windchill and a lesson plan that goes with it: NPR windchill podcast
Lesson Plan - middle school
Heat transfer lessons
The above chart has changed over time,
but is used to indicate at what combined wind speed and temperatures
exposed flesh will be damagaed. When will your nose, ear lobes, cheeks,
fingers and toes be at risk of frostbite.