The present invention generally relates to a method for authenticating a finger of a user of an electronic device comprising a fingerprint sensor for sensing a fingerprint pattern, the method comprising the steps of: acquiring a candidate fingerprint image; determining, based on the candidate fingerprint image, a humidity level indication indicative of the humidity level of the finger; performing an authentication pre-process based on the humidity level indication; performing a fingerprint authentication process based on the pre-process to authenticate the user.