Tonga in January

May through October gives you the sweet spot – dry season with trade winds keeping things comfortable. Temperatures hover around 75-80°F, perfect for diving and beach days. This is also whale season. Humpbacks migrate through Tongan waters from July to November, and you can actually swim with them here – one of the few places on earth where it's legal. The wet season from November to April brings higher humidity, more rain, and cyclone risk. But here's the upside: fewer tourists and lower accommodation prices. Just avoid January through March when cyclone activity peaks. The shoulder months of May and October offer the best deals while still hitting good weather. Book whale swimming tours early – operators limit group sizes and spots fill up fast.