Fernando de Noronha in December

April through November offers the calmest seas and best diving conditions. The dry season runs May through October, with less rain and clearer skies for those Instagram shots. But here's what matters most: sea conditions. From December through March, the Atlantic gets choppy and diving visibility drops. You'll still see dolphins year-round, but the underwater magic really shines during the calmer months. Temperatures stay steady around 80°F year-round. Book at least six months ahead regardless of when you visit — those 460 daily visitor spots fill up fast, especially during Brazilian holidays.