The largest peak discharges (~ 50%) take place during normal phase of ENSO. The amount of rainfall accumulated for two-weeks is critical for the magnitude of peak discharges. A discharge > 1140 m3 s− 1 inundates with > 0.5 m of depth the lower course of Ameca River (~ 5.7 km2). The number of hurricanes and tropical storms and rainfall are the highest in the summer of normal phase of ENSO.