There are lots of little signs that show you what the wind is doing- the grass, the leaves, the mirage, the cloud movement overhead, even the lay of the land will tell an experienced guy what kind of wind to expect. Morning and evening have different wind currents in high country. Of course, a good wind meter will tell you what the wind at the shooter's location is doing, and it is a good way for a guy that's new to wind reading to learn what a 5 mph wind feels and looks like, versus a 15 mph wind, etc. Also remember that wind in the open air moves a bit quicker than wind moving along the ground, so even if your wind meter shows 10 mph on the edge of a canyon, it's likely going a bit quicker in the middle of the canyon between the two sides, which your bullet has to pass through.
The best way to learn how to read the wind, is to get a few tips and pointers, and then shoot, shoot, and shoot some more.
