South pacific weather patters including seasons, tropical cyclones, rainfall, sunshine hours and south pacific climate charts.
Apart from New Zealand in the far south, the Pacific Islands are tropical in climate and experience only small fluctuations in temperature and daylight throughout the tear. Typical daytime temperatures are between 24 and 31oC (75 - 89oC) with only a few degrees drop at night time. Of greater significance to holiday-makers though is 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. Over a 15-year average, 28 cyclones per year buzz around the Pacific. Few of these reach the intense levels causing major damage and casualties - cyclones are upgraded to hurricane status in the south pacific and to typhoon status in the north pacific. Now, the Pacific is a huge area. Only a few of these cyclones will hit land direct, and even when they do, their path of destruction is usually only 50 miles wide. So, the chance of actually holidaying in the path of a cyclone is very low. Instead of staying away during the cyclone season, as many tourists do, you would better be advised to steer clear of a region after a hurricane has hit - the damage it causes to beaches, reefs, houses and vegetation doesn't make for a pretty site for at least 6 months.
The Pacific season is divided into two - the humid and slightly hotter "wet" season, and the less humid, slightly cooler "dry" season. North of the equator (Micronesia) the more favoured 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 (Fiji, Tonga, Samoa, Cook Island and Tahiti) the dry season is between May and November.
Dry and Wet are very loose terms - the amount and frequency of rainfall is determined as much by the local topography of the islands as to the seasons. Reading weather charts on the Pacific main cities gives little indication as to the weather around the offshore islands.
The reason for this is the trade winds. The trade winds is a natural phenomena caused by the rotating earth that causes air flow and currents to blow from the south-east in the southern hemisphere and north-east in the northern hemisphere. Any large island will therefore trap moisture from this air flow causing cloud cover and rain on the windward side and a dry region on the leeward side of the island.
