The best time to visit Rosario is during the dry season, which typically runs from December to May, offering warm, sunny weather superb for exploring.During these months, you'll experience less rainfall and comfortable temperatures, making it ideal for enjoying the local beaches and outdoor activities. The sea is usually calm and clear, which is excellent for swimming, snorkelling, or island hopping.For those looking to avoid the peak tourist crowds and still enjoy good weather, the shoulder months of May and December are particularly appealing. You'll often find slightly fewer people and potentially better rates on accommodation and flights, while still benefiting from plenty of sunshine.The rainy season, from June to November, brings more frequent and sometimes heavy rainfall, which can occasionally disrupt travel plans and outdoor excursions.