Extremes of climate occur globally but for the low-latitude Pacific the most common, threatening and destructive extremes come in the form of tropical cyclones and droughts. They occur regularly and both types of event have destructive and debilitating impacts on certain countries and islands within the region. Tropical cyclones and droughts periodically impact islands located in parts of the Pacific that are not usually affected by such events. The most important factor influencing the incidence of these extremes of climatic variability across the Pacific Ocean is the EI Nino-Southern Oscillation (ENSO) phenomenon. Occurring at present every 3-5 years, this large-scale ocean atmosphere interaction involves the fluctuation of pressure systems on either side of the Pacific which alter temperature, rainfall, wind and pressure distribution across the region and in tum influence the distribution of criteria required for the formation of tropical cyclones and occurrence of droughts. In addition to coping with current impacts of tropical cyclones and droughts, decision-makers of Pacific island countries now have to contend with the prospect of such events, including ENSO, becoming more frequent if global climate changes in the future as predicted. In order to understand present climatic characteristics there is a need to gain a greater understanding of climate in the more recent past.