Idanha A Nova, Portugal offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Idanha A Nova is known for its proximity to the stunning natural landscapes of the International Tagus Natural Park. The best time to travel to Idanha-a-Nova, Portugal, is during late spring to early autumn (May to September), when the average air temperature ranges from 20°C to 30°C (68°F to 86°F), and nearby river water temperatures are generally comfortable for swimming, averaging around 20°C to 25°C (68°F to 77°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!