Observe the wind vane closely, using a pair of low-power binoculars if necessary. Identify the front and the back of the weather vane by looking at both ends. The wind vane pointer is the sharp pointed end which may appear like an arrowhead or a rounded bullet. The rear end is termed the "fin" or the "aft" of the weather vane. This fin is pushed by the wind, causing the pointed end to point in the direction the wind is coming from.
Stand facing the same direction in which the sharp end of the weather vane is pointing while holding a compass in one of your hands.
Identify the relative wind direction according to your compass. Standard weather reporting convention is to state the direction the wind is coming from.