How to Calculate the Effects of Wind on Trajectory
- 1). Estimate the wind speed. Watch the movement of trees and grass. Figure the wind to be approximately two to four miles per hour if the grass moves occasionally, approximately five to nine miles per hour if the grass leans and smaller tree limbs move, approximately 10 to 14 miles per hour if thicker tree limbs move and 15 to 20 miles per hour if trees sway and the grass constantly moves.
- 2). Make a note of the wind direction. Drop a handful of grass or sand to visualize the current of the wind if you have trouble determining. Visualize a clock with 12 immediately in front of you and 6 directly behind. Record the direction from which the wind comes according to corresponding time on the clock.
- 3). Aim at a target a known distance away. Launch your projectile at the target. Mark the position where it hit.
- 4). Measure the distance and direction from the target that your projectile hit. Divide the distance away from the target that the projectile hit by the distance between you and the target at the time you launched the projectile. For example, if you fired at a target that was 100 yards away and the bullet hit two inches to the target's 6 o'clock then the wind changed the trajectory of your bullet by 2 inches per 100 yards.
