windometer

Plain and simple: an anemometer.
An anemometer is an instrument used for measuring wind speed.

Winds were clocked with my stupid sodding "rotten cat pee yellow" portable digital "windometer" (as JD from JD Quad in the UK calls them even though those things are actually called, "anemometers") ;-) as being variable to 3.60mph (4.36kph) at the surface.