# Winter Experiments

## The Wind-Chill Factor

Cold weather feels even colder when it's windy. Professional weather forecasters call this the "wind-chill factor." Find out how it works in this winter experiment.

The Wind-Chill Factor Experiment

 Wind chill tells you how cold it is outside.

What You'll Need:

Thermometer
Wind-speed gauge

Your body is normally surrounded by a thin layer of warm air, and it protects you. The wind, however, actually blows away that layer of warm air. So, you feel much colder on windy days.

Using a thermometer, measure the temperature. Then calculate the speed of the wind with the wind-speed gauge. Combine the numbers on the chart below to determine the wind-chill factor. Use the wind-chill factor to help you dress for the weather. Bundle up for how cold it feels, not how cold it is!

Find the place on the chart where the wind speed and the temperature meet. That's the wind-chill factor. Example: If the wind speed is 10 mph and the temperature is 25 degrees, the wind-chill factor is 10 degrees.

 Wind Speed, mph Temperature, Fahrenheit
 0 30 25 20 15 10 5 0 5 27 22 16 11 6 0 -5 10 16 10 3 -3 -9 -15 -22 15 9 2 -5 -11 -18 -25 -31 20 4 -3 -10 -17 -24 -31 -39 25 1 -7 -15 -22 -29 -36 -44 30 -2 -11 -18 -27 -33 -43 -49

On the next page, find out how to measure hail using a few simple steps.

For more fun activities and winter crafts, check out: