Tonga Islands in May

April through October delivers the best weather — dry season with temperatures around 25°C (77°F) and steady trade winds. This is also whale season from July to October, when humpbacks migrate here from Antarctica to breed and give birth. May and June offer the sweet spot: perfect weather before peak whale season crowds. September and October can get busy with Australian and New Zealand school holidays, but the whale activity peaks then too. November through March brings cyclone season. Not every year sees major storms, but when they hit, they shut down islands completely. Temperatures climb to 30°C+ (86°F+) with high humidity. Some resorts and tour operators close during these months. But if you can handle the heat and don't mind occasional rain, you'll have beaches to yourself and better prices.