An apparatus and a method used to determine the speed and direction of the wind experienced by a wind turbine are provided. The apparatus comprises at least one sensor fixed to the rotor of the wind turbine, an angular sensor to measure the angular position of the rotor of the wind turbine, and a circuit which converts the relationship between the output of the at least one sensor and the output of the angular sensor into the speed and direction of the wind experienced by the wind turbine. According to the invention, the sensing apparatus can measure the wind speed and direction in three dimensions. In addition, mounting the sensors directly to the rotor of the wind turbine results in a very simple and robust installation. Mounting the sensors directly to the rotor also eliminates the turbulence from the rotor and the nacelle of the wind turbine from affecting the sensors.