The main Cook Islands are about the same distance from the equator as Hawaii and have a similarly pleasant tropical climate. Rarotonga is refreshingly cooler than Tahiti and Moorea.
Rain clouds hang over Rarotonga's interior much of the year, but the coast is often sunny, and the rain often comes in brief, heavy downpours. The other islands are drier and can even experience severe water shortages. Winter evenings June-August can be cool.
On both Rarotonga and Aitutaki, the best combination of prolonged hours of sunshine, fresh temperatures, and minimal rainfall runs July-September.
May-October, the trade winds blow steadily from the southeast in the southern Cooks and from the east in the more humid northern Cooks; the rest of the year winds are sometimes from the southwest or west (often a sign of bad weather).
The summer hurricane season is November to April, with an average of one every other year, coming from the direction of Samoa. In December 2001 Hurricane Trina roared across Mangaia, flooding the taro fields and turning the sea red with eroded soil. An unusual series of five hurricanes hit Rarotonga in 2005 but the damage was soon repaired.