An analysis of the seasonal and interannual rainfall distributions in El Salvador is made. The seasonal distributions show that the rainy season occurs from May to October and the dry season from November to April, with transition periods between them. In the rainy season the distribution is bimodal, with the primary maximum occurring in most of the cases in September and the secondary maximum in June. In the rainy season, June and August show a marked decrease in rainfall, clearly observed in the coastal and eastern zone of the country, but not in some stations of the northern zone or on the southern mountain range. Large rainfall values are observed in the northèrn-western zone, near the border with Honduras. They may also occur around the southern mountain range. February shows the lowest rainfall values. In July and August, there is a significative rainfall decrease in the eastern zone, with a variation up to 100 mm. From the interannual distributions, it is found that in many of the stations the decrease in rainfall occurs in some ENSO events, particularly in the strong and very strong ones. In other events, there is not a significative decrease in rainfall. The trends of many series show a decrease in rainfall through the years. On the contrary, in the station Colon Casa Blanca there is a positive rainfall trend.
