What does "wind direction" refer to?

Wind direction refers specifically to the direction from which the wind is blowing. This concept is fundamental in meteorology because it helps describe weather patterns and the movement of air masses. For example, if the wind is said to be coming from the north, it indicates that the air is moving southward. This distinction is crucial for various applications, including aviation, sailing, and weather forecasting.

The other options provide different definitions that do not accurately capture the essence of wind direction. Trajectory relates more to the path of the wind rather than its source. Wind speed describes how fast the wind is moving, while the area affected by wind refers to the geographic influence of the wind's flow but does not define its direction. Understanding these nuances helps contextualize how wind direction plays a crucial role in weather observations and predictions.