What meteorological instrument is best for measuring wind direction?

The wind vane is the meteorological instrument best suited for measuring wind direction. This device operates on the principle of aerodynamic forces, with a pointer or blade that is mounted on a pivot. As the wind blows, it rotates the vane to align with the wind direction, indicating which way the wind is coming from. The design typically includes cardinal direction markings, allowing for clear and easy reading.

Other instruments serve specific purposes but do not measure wind direction. For instance, a thermometer measures temperature and provides no information about air movement. An anemometer assesses wind speed, giving valuable data about the intensity of the wind, yet it does not indicate the direction from which the wind originates. A barometer measures atmospheric pressure, essential for weather forecasting but again unrelated to wind direction. Thus, the wind vane is uniquely designed for the purpose of indicating where the wind is blowing from, making it the appropriate choice for measuring wind direction.