Saint Just, United Kingdom offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Saint Just, England, United Kingdom, is known for its proximity to the UNESCO World Heritage Site of the Cornwall and West Devon Mining Landscape. The best time to travel to Saint Just, United Kingdom, is during the summer months of June to August, when the average air temperature is around 16-19°C (61-66°F) and the sea temperature is approximately 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!