The best time to visit Grandes Rocques is between May and September, when the weather is at its most pleasant, offering the ideal conditions for enjoying the island's natural beauty and outdoor activities.During these months, the temperatures are mild, typically ranging from 15°C to 20°C, and there are more hours of sunshine. This makes it superb for exploring the coastal paths, spending time on the beaches, or enjoying water sports. The sea temperatures are also warmer, which is a bonus for swimming.For those who enjoy a lively option, July and August are particularly popular, with many local events and festivals taking place across Guernsey. However, if you prefer a slightly quieter experience with still excellent weather, late May, June, and September are superb choices.