In this paper the problem of estimation and correction of wind effects on a quadrotor UAV, without using wind sensors, is discussed. A large body of research addresses the effects of wind on a quadrotor, however most of them consider it only as a disturbance in their control loop and, for this reason, they solved the problem compensating for the wind with a powerful controller. The main part of this paper is related to the modeling of wind on a quadrotor and to the wind tunnel tests performed at the IFD wind tunnel of ETH Zurich. The approach presented can be used as a starting point for future works. The results obtained in the wind tunnel are really promising for the formulation of a complete aerodynamic model of the quadrotor that has been missing until now.