A method of determining operating conditions of an exterior aircraft light comprising at least one light source includes: operating the at least one light source of the exterior aircraft light; repeatedly detecting light with a light detector, which is located at the exterior aircraft light and configured for providing light detection values; determining a smallest light detection value (Imin) provided by the light detector within a first period of time, and storing said smallest light detection value (Imin) as an element of a series of smallest light detection values (Imin); and evaluating the light detection values and the series of smallest light detection values (Imin) for detecting erosion of an optical component of the exterior aircraft light, for detecting the presence of ambient light and/or for detecting the presence of fog and/or clouds in front of the exterior aircraft light.