Cobo, Guernsey offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Cobo, Castel, Guernsey is known for Cobo Bay, a picturesque beach popular for its stunning sunsets and coastal scenery. The best time to travel to Cobo, Guernsey, is from June to September, with average air temperatures around 15-20°C (59-68°F) and water temperatures around 15-17°C (59-63°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!