Con Son Island in August

November through April delivers perfect weather with temperatures around 26°C and minimal rain. December and January see the most visitors, so expect higher prices and fuller flights. The shoulder months of November and April offer the sweet spot — great weather with fewer crowds and better deals. Avoid May through October when monsoons bring heavy rain and rough seas that can cancel diving trips. But here's a secret: September and October, despite the rain, offer the best turtle watching since it's peak nesting season. The weather breaks between storms, and you'll practically have the beaches to yourself. Water temperature stays warm year-round at 27°C, perfect for swimming and diving regardless of season.