Dornum, Germany offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Dornum is known for its historic Dornum Castle and the picturesque East Frisian landscape. The best time to travel to Dornum, Germany, is from June to August, when the average air temperature is around 18°C (64°F) and the North Sea water temperature is approximately 17°C (63°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!