The best time to go to Boossa, Sri Lanka, is during the dry season, which runs from December to March.During these months, you'll experience warm, sunny weather with minimal rainfall, making it ideal for enjoying the beautiful beaches and outdoor activities. The sea is calm and great for swimming, snorkelling, and other water sports. This period is also popular for whale watching, with sightings of blue whales and sperm whales common off the coast.For those looking for a quieter experience, the shoulder seasons of April to May and September to November can also be a good option. While there might be occasional showers, the weather is still generally pleasant, and the resort areas are less crowded.