There are plenty of clues out there as to wind speed and direction. The best of all especially at this time of the year is heat haze. That tells you instantly the direction.
Using your ears is a good technique. Stand with your back to the wind, then slowly turn your head left and right until the noise in both ears is identical. That gives you the direction. If you walk away from the wind, and find that at a good walking pace you can't feel it any more, then the wind will be at the same speed - roughly - as your pace, say 4 mph.
For a basic start I look at the clouds if there are any and then ask myself why should the wind at ground level be in a different direction. There's usually a good reason, or no reason.