This paper studies droughts, floods and tsunamis in Greek mythology. Drought appears as a period of abnormality produced by some transgression that must be repaired. It is also a driving force that promotes emigration in search of suitable places for life. Floods are complex. Some myths allude to floods sent by Zeus to purify the earth. Others tell of heroes fighting against rivers, symbolising human efforts to control floods. Others refer to sea floods sent by Posidon. The latter sometimes suggest tsunamis. Pervasive natural disasters – drought– leave a deeper imprint on the myths than intensive natural disasters –floods and tsunamis– which seem to have less specific weight in the collective memory of ancient Greek societies.