From June through October, the Galápagos moves into one of its cooler stretches of the year, driven by the Humboldt Current pushing up from the south. Water temperatures during this window typically sit between 16°C and 24°C (60°F to 75°F), while air temperatures hover around a mild 20°C (68°F). Currents at the dive sites can run anywhere from 1 to 5 knots depending on location and day, which is part of what makes some Galápagos sites better suited to experienced divers.
The cooler water isn't just a comfort consideration — it's ecologically significant. Colder water carries more nutrients, and that nutrient load is a major reason this season draws in larger marine life, including whale sharks and hammerhead sharks, in greater numbers. Divers choosing a Galápagos trip for big pelagic encounters generally have this June-to-October window in mind, accepting a slightly heavier wetsuit in exchange for a better shot at these sightings.