Meteorological data at Dunkirk between 1956 and 2001, show two periods of higher storminess between 1956 and 1962 and between 1972 to 1977. Tide-gauge records from Dunkirk harbor show similar results, the frequency of high magnitude storm surges (≥100 cm) being higher during the 1960's and the second half of the 1970's. The assessment of the impacts of storm surges on coastal erosion was carried out through the use of a storm erosion susceptibility index (SESI) which integrates the magnitude of the storm surge, duration of the event, and wave height. At a medium time-scale (decades), no direct relationship was observed between the SESI and coastline evolution because potential impacts of storm surges highly depend on the upper beach morphology at the time of the event. At a short time scale, however, the use of the SESI appears to be useful for evaluating the potential effects of storms on shorelines.