The Pacific Islands are tropical in climate and experience only small fluctuations in temperature and daylight throughout the year except New Zealand in the far south,. Typical daytime temperatures are between 24 and 31oC with only a few degrees drop at night time. At higher elevations, temperatures typically drop at the rate of 1.7° C for every rise in elevation of 300 m.
The humidity level, which when high can be uncomfortable and brings severe downpours. Humidity increases during the tropical summer (Nov-Apr) and during this time the risk of tropical cyclones is present in the southern parts of the south pacific, notably Fiji, Samoa, Tonga, Cook Island and French Polynesia. There are, on the average some two dozen cyclones a year in the Pacific area. Only a few of these reach the intense levels causing major damage and casualties . The western Pacific also has many tropical cyclones. North of the equator most such storms occur between July and November. South of the equator the stormy season begins about November and ends about March. The heavy wind and rains brought by these storms often cause devastating loss of life and property.
The Pacific season is divided into the humid and slightly hotter "wet" season, and the less humid, slightly cooler "dry" season. North of the equator the preferred dry season is between November and May. Hawaii is far enough north that winter and summer seasons are used as opposed to dry and wet, although here cyclones can still be a threat from August to November. South of the Equator , which includes Fiji, Tonga, Samoa, Cook Island and Tahiti) the dry season is between May and November.
In parts of the central and western Pacific, monsoon climates prevail. In monsoon climates, moisture-bearing winds reverse direction once a year, creating a distinct wet season and a dry season. Because of monsoon conditions and differences in elevation, amount of rainfall, seasonal and annual, varies greatly from island to island and even on different parts of larger islands.The western slopes of these islands are relatively dry.
Depending on the worst case scenario of global warming, the studies suggest that there will be a one metre sea level rise with negative impacts on tourism, freshwater availability and quality, aquaculture, agriculture, human settlements, financial services and human health. Storm surges are likely to have a harmful impact on low-lying islands. Shifts in rainfall regimes and any increase in tropical cyclone intensity and frequency greatly amplify the impact of sea level rise.