The best time to visit Aogashima is during the warmer months, specifically from July to September, when the weather is most favourable for travel and outdoor activities.
During this period, the sea conditions are generally calmer, which significantly increases the likelihood of ferry services operating as scheduled. As Aogashima is an isolated volcanic island, ferry cancellations due to rough seas are a real possibility outside of these months, which can disrupt travel plans. The warmer temperatures also make activities like swimming, snorkelling, and hiking more enjoyable.
This timeframe is particularly good for solo travellers or couples seeking an adventurous getaway. The clear skies and warm evenings are great for stargazing, as Aogashima boasts exceptionally dark nights.