South Pacific Weather
The climate of the South Pacific islands is tropical yearround. There's a hotter, more humid period from November to April, and a cooler, drier time from May to October. The countries closer to the equator (Samoa, Tuvalu, Solomon Islands) are generally warmer than those further south (Fiji, Tonga, New Caledonia, Cook Islands).
Climate change has made South Pacific weather forecasts less predictable than they were. During the official "rainy season" from November to April, you may now encounter long spells of clear sunny weather, and "dry season" no longer guarantees that it will be dry. The heavy rains are generally followed by sunny skies, and much of the other rain falls at night.
November to April is the official hurricane season, and global warming is having an impact. In 1997 Hurricane Keli was the first South Pacific hurricane ever to arrive in June, and Hurricane Zoe in 2002 was the most powerful yet recorded in the Pacific. An increasingly frequent climate cycle known as El Nino (the movement of warm water east toward South America) can bring prolonged rains to French Polynesia and drought to Melanesia.
The best time for a South Pacific vacation? Late April to August is great because that's when Air New Zealand offers low season airfares on flights to Fiji, Tonga, Samoa, and the Cook Islands. The humidity will be lower then too! The downside is that Australians, New Zealanders, and French crowd out the island resorts in July and August. In February and March, the same hotels often stand empty (watch for accommodation specials those months).
May to October is the South Pacific cruising season when the southeast trade winds push cruising yachts west from French Polynesia to Tonga, Fiji, and Vanuatu. By late October, most boats will be heading south to sit out the hurricane season in New Zealand and Australia. Due to the prevailing winds, sea journeys all across the South Pacific are smoother westbound than eastbound, a good thing to know if you're prone to seasickness.
The climate here is not unlike that of Hawaii. July to September will be cool and sunny, unless it's an El Nino year. (more information)
The Humboldt Current keeps the island moist and cool. The wettest months are March to June, the coolest are July to October. It never snows or freezes, but drizzle and mist are common. (more information)
The windward slopes of the high islands catch the southeast trades, and are green and moist as a result. The northwest coasts and smaller offshore islands tend to be sunny and dry. During the drier season (May to November), the reef waters are clearest for the scuba diver. (more information)
Like Fiji, New Caledonia's main island is high enough to create a rain shadow along the northwest coast. From December to March cyclonic depressions can cause flooding, but in general, the climate is moderate. (more information)
Sultry Samoa is hot and humid yearround, although the cooling southeast trade winds mitigate this from May to October. The rainfall can be heavy, but even in summer you may have long periods of fine, sunny weather. From December to March, occasional hurricanes ravage Samoa and Fiji. (more information)
The Solomon Islands are hot and humid yearround, with the rainfall peaking from December to March. Although hurricanes often build up over these warm waters, they generally move south or east and do little damage here. (more information)
The refreshing southeast trade winds blow consistently from May to August, varying to easterlies from September to December. The northeast trades from January to April coincide with the hurricane season, although hurricanes are less frequent here than in Samoa, Fiji, and Vanuatu. (more information)
Due to its southerly location, Tonga is always cooler and less humid than Samoa. Hurricanes blow down from the north once or twice a year. (more information)
Tuvalu is hotter than Fiji, though the sea breezes make it rather pleasant. As the seas warm up, hurricanes become stronger, more frequent, and less predictable. Climate change may totally submerge this low-lying country by the end of this century. (more information)
Vanuatu becomes hotter and rainier as you travel north. The north is also one of the most hurricane-prone regions of the South Pacific. Throughout the country, winds from the north or west augur bad weather. (more information)