Fir Na Creeve, Ireland offers 1 beach perfect for sunbathing, surfing, swimming, and more. Fir Na Creeve, Ulster, Ireland, is known for the historic Fir Na Creeve Castle and the annual Ulster Cultural Festival. The best time to travel to Fir Na Creeve, Ireland, is from May to September, with average air temperatures around 15-20°C (59-68°F) and water temperatures around 12-16°C (54-61°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!