Question

Why anemometers and wind vanes are usually kept on high buildings and towers?

Answer 1

as the speed of air is highest in the upper part of stratosphere hence it is kept on high buildings

Answer 2

Anemometer and wind vane are usually kept at high buildings and tower to provide accurate wind directions. For this they need to be high above the ground. Near the ground, obstacles such as buildings and trees cause winds be deflected or swirl around, so that it is not possible to determine the correct wind direction.