Rynn, Ireland offers 1 beach perfect for sunbathing, surfing, swimming, and more. Rynn, Connaught, Ireland, is known for Lough Rynn Castle and its beautiful gardens. The best time to travel to Rynn, Ireland, is during the summer months of June to August, when the average air temperature is around 15-20°C (59-68°F) and the water temperature is approximately 14-16°C (57-61°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!