Weather in Saint Helena, Ascension and Tristan da Cunha

Saint Helena enjoys a subtropical climate moderated by southeast trade winds, making temperatures remarkably stable year-round between 18°C and 28°C. There is no sharply defined dry or wet season — rainfall is spread relatively evenly across the year, with the highest interior areas receiving the most. The warmest months from November through March coincide with the Southern Hemisphere summer and offer the best conditions for swimming and snorkelling, including whale shark encounters off the island's coast during this period.

May through September brings slightly cooler temperatures and the best conditions for hiking Saint Helena's spectacular ravine trails and cloud forest paths. October and November are considered the most pleasant months overall — warm enough for the beach, clear enough for the extraordinary views from Diana's Peak, and quiet enough to enjoy the island without the small influx of visitors that the twice-weekly flight can bring. Whale watching season (humpback whales) typically runs from July through October, while whale sharks are most reliably sighted from November through May. Travellers should book the island's very limited accommodation well in advance regardless of season.