How to Gauge Wind Speed

Wind speed is a quantifiable measure of the atmosphere around you, which is helpful in determining weather patterns. Wind speed can indicate when a storm is about to occur and is one of the ways in which meteorologists classify hurricanes. An instrument that measures wind speed is known as an anemometer. Elementary anemometers can be made using materials commonly found in the home, such as paper cups, tape and scissors.

• 1

  Cut the cardboard into two rectangular strips. The strips should be as wide as one paper cup and as long as two paper cups.

• 2

  Cross the two pieces of cardboard together in an "X" shape. Staple them together.

• 3

  Staple the paper cups to the ends of the cardboard "X." All cups should be on the same side of the cardboard. Mark one of the cups with a particular color marker.

• 4

  Stab the pencil, point side down, into the florist's foam so that it stands straight up with its eraser showing at the top. Place the cardboard "X" centered over the eraser of the pencil, and secure it with the thumbtack. Push the thumbtack in enough to keep the cardboard in place yet retaining its ability to spin.

• 5

  Set your timer for one minute. Place your anemometer in a location with a good draft or wind. Hold the marked cup still. Release the anemometer to allow it to freely spin at the same time you start the timer. Count the revolutions the marked cup makes in that one minute.

• 6

  Multiply the number of revolutions by the circumference of the anemometer, which is pi times diameter. This will give you the distance the marked cup traveled in one minute. Find the diameter by measuring the length of one cardboard strip using a ruler.

  Distance = diameter by pi by number of revolutions

• 7

  Divide the distance traveled by the marked cup by the time it traveled (one minute) to determine wind speed. Units should be in inches per minute. Calculate wind speed in miles per hour by dividing by 1,056.