Time: 4;54PM
Location: Outside of YMCA, Pierre SD
Temp: ~10°F
Wind:~ 15 mph
Skies: Clear
I took this picture to document the wind. The wind is a constant in central South Dakota so learning how to tell wind speed without an anemometer is a handy skill. Probably the easiest way to do this is to learn a modified Beaufort scale which was invented as a visual way of determining wind speed while at sea. I like the one from Wikipedia. I have even further simplified it for my own purposes to be able to form a rough estimate.
Keep in mind that a rough estimate is not the same as taking a reading. The purposes of rough estimates is to stand in for when you don't have equipment. The more estimates you take and compare with readings, the better your estimates will become.
The flag in this picture was flapping which means it drops from time to time. A flapping flag is somewhere between 10 and 15 miles per hour.
~ 5 mph: Feel a breeze, leaves moving. (This only works when the trees are in leaf, obviously)
~10 mph: Twigs moving on trees, ripples on water
~ 15 mph: Small branches moving, flags flapping, waves on water
~ 20 mph: Small trees sway, flags waving, waves break with white caps
~ 25 mph: Large branches moving, large flags straight out, large white caps
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