The Cook Islands epitomize the dream of an idyllic island in the south Pacific. Scattered like pearls in the vast ocean, they lie between longitude 156° and 170°W and between latitude 8° and 23°S, some 3500km/21,700mi northeast of New Zealand. Their charms - unspoiled natural beauty and palm-shaded beaches - have not been ruined by mass tourism.
The Cook Islands consist of a northern group of seven and a southern group of eight islands, lying 1000km apart. Their national territory extends over a total area of 2,201,490sq.km/1,364,923sq.mi, but their land area is no more than 240sq.km/150sq.mi. Lagoons within the islands cover 566sq.km/350sq.mi. The total area of the islands with their lagoons is thus only 0.04 per cent of the national territory.
Like most of the Pacific islands the Cook Islands are either purely volcanic or coral atolls on a basalt base. Five types of island can be distinguished: the high volcanic island of Rarotonga; the raised coral islands of Mangaia, Mauke, Atiu and Mitiaro, with a volcanic core and a surrounding plain of coralline limestone; Aitutaki, consisting of a central volcanic island and a surrounding barrier reef; the atolls of Manuae, Palmerston, Penrhyn, Manihiki, Rakahanga, Pukapuka and Suwarrow; Takutea and Nassau, islands of sand on a coralline limestone base.
Mangaia, Atiu, Mauke and Mitiaro are islands of a type that is very rare in the Pacific. In a term borrowed from the Maori language, they are described as makatea islands: islands that consist of a central volcanic hill surrounded by a broad, gently sloping plain of coralline limestone. They originated soon after the ending of volcanic activity, when the volcanic islands were gradually sinking into the sea. As they sank their fringing coral reefs rose. Later, forces from the earth's interior thrust the extinct volcanoes with their fringing reefs up again, and these were then leveled off by the surf and later by weathering.
The Cook Islands lie within the sphere of influence of the marine climate of the tropics, which is characterized by slight annual variations in temperature, high air humidity and rainfall throughout the year. Between December and April the northern group of islands falls within the inner tropical convergence zone. In this area whirlwinds can occur, hitting the northern islands in particular between December and March.
High temperatures combined with high air humidity produce a sultry and sometimes extremely oppressive climate on all the islands. The months January to April are particularly trying: even at night the air is not much cooler. December to March are the rainiest months (annual average c 2200mm). Overcast days with rain, however, are rare even during these months. Prolonged periods of bad weather occur only during the (relatively rare) passage of tropical disturbances and storms.