USING FLAGS TO ESTIMATE THE WIND SPEED
You can use an ordinary flag to give you a good indication of the wind speed. Take a look at the table below.
Bft = Beaufort Scale Wind Speed
0 Bft – I assume you can guess what this looks like.
1 Bft – the flag only occasionally flips open, the outer end hangs lower.
2 Bft – the flag is mostly extended, the waves are deep, a large portion of the outer top corner flips back and forth.
3 Bft – the flag is completely extended, the waves are faster and smaller than 2 Bft.
4 Bft and Up – the flag is still completely extended, the waves are faster than 3 Bft. The changes from 4 Bft and up are more subtle and harder to distinguish from each other, but this is of little concern since the choice is not what kite to fly, but whether to fly a kite at all.
These flags are 5 ft. by 7 ft. (1.5m by 2m) but size makes little difference.
(If you are using Internet Explorer and have JavaScript disabled then the flag animations are about 3/4 normal speed. Netscape plays the animations at normal speed with or without JavaScript enabled.)