The Galápagos Islands have a unusual climate for a tropical archipelago. Sitting right on the equator, you might expect steamy jungle heat, but cold ocean currents keep temperatures surprisingly mild, averaging between 68°F and 86°F year-round. The islands cycle between two distinct seasons: a warm, rainy period from January to May and a cool, dry period from June to December. What makes the climate truly unusual is how dramatically it shifts across short distances, from bone-dry coastal lowlands to misty, green highlands on the same island.
Two Seasons Shape the Year
The warm and rainy season runs from January through May. Air temperatures during these months reach highs around 86°F and dip to about 72–73°F at night. Skies tend to be sunny between bursts of heavy tropical rain, and humidity runs high. Most of the year’s rainfall in coastal areas falls during this window.
The cool and dry season, often called the garúa season, stretches from June through December. Daytime highs drop to the mid-70s, and lows hover around 68°F. Despite the name “dry season,” moisture is still present. It just arrives differently: as a persistent, fine mist called garúa rather than as downpours. Stratocumulus clouds accumulate around the tops of volcanoes, sometimes sitting there for weeks. The highlands stay damp and green while coastal areas see clearer skies.
Ocean Currents Drive Everything
The Galápagos sit at the intersection of several major ocean currents, and these currents are the primary engine behind the islands’ climate. The Humboldt Current sweeps north from Antarctica along the western edge of South America, carrying cold, nutrient-rich water. The Cromwell Current travels thousands of kilometers from the central Pacific, slams into the western islands, and pushes deep cold water to the surface. Together, these cold currents are why an equatorial archipelago feels more subtropical than tropical for much of the year.
From the north, the Panama Current flows south from Central America carrying warm water. From May through December, it collides with the cold Humboldt Current. That collision creates the cool mist and cloud cover that define the garúa season. Around December, the warm Panama Current becomes dominant, pushing humidity and heavy rains southward into the islands and kicking off the wet season. The South Equatorial Current also moves through the archipelago from east to west, adding another layer of warm surface water to the mix.
Rainfall Varies Dramatically by Elevation
The Galápagos sit in the Pacific Dry Belt, and in an average year, most of the land area receives surprisingly little rain. Coastal and arid lowland zones on islands like Santa Cruz and San Cristóbal get about 500 mm (roughly 20 inches) of rain annually, with most of it concentrated in the warm season. During the cool, dry months, those same lowland areas average only about 130 mm total.
The highlands tell a completely different story. On larger, taller islands, annual rainfall ranges from about 1,050 mm to 1,670 mm (41 to 66 inches). The difference between wet and dry seasons is far less dramatic at higher elevations because the garúa mist provides a steady source of moisture even when it isn’t technically raining. An inversion layer of moisture from the ocean gets intercepted by the higher volcanic peaks and condenses into continuous mist, keeping those upper zones lush year-round.
Three Climate Zones on a Single Island
On the larger islands, you can walk from a near-desert landscape to a cloud forest within a few hours. The Galápagos Conservancy and other researchers identify three broad vegetation zones that reflect distinct microclimates stacked by altitude.
- Coastal zone: A narrow strip near the shore dominated by salt-tolerant plants. Hot, dry, and wind-exposed.
- Arid zone: The most extensive zone across the archipelago, covered in cacti, leafless shrubs, and brown-grey vegetation that only greens up during the brief rains. This landscape covers the majority of the islands’ land area and looks more like a desert than a tropical environment.
- Humid highlands: Found only on the larger, taller islands. Dense Scalesia forests grow here, their branches draped in mosses and epiphytes. This zone stays green year-round thanks to garúa moisture and higher rainfall.
Smaller, low-lying islands never reach the elevation needed to intercept the mist layer, so they remain arid throughout the year. This is why the Galápagos can look so barren in photographs despite sitting on the equator.
Water Temperatures and What They Mean for Visitors
Sea surface temperatures follow the same seasonal split. During the warm season (January through May), water temperatures range from about 73°F to 77°F, warm enough for comfortable snorkeling without much gear. March tends to be the warmest month both in the air and the water, with air temperatures reaching up to 87°F and water around 77°F.
During the garúa season, ocean temperatures drop noticeably. From June through November, water temperatures fall to 66–72°F. August and September are the coldest months in the water, averaging around 71°F. A wetsuit makes a real difference if you plan to snorkel during this period. The tradeoff is that the colder, nutrient-rich water attracts more marine life: whales, dolphins, and large schools of fish are more active in these months.
El Niño and Climate Swings
The Galápagos are highly sensitive to El Niño events, which temporarily overwhelm the normal current patterns. When El Niño strengthens, the warm Panama Current dominates for longer, pushing sea surface temperatures well above average and bringing unusually heavy rains. During strong El Niño years, coastal lowlands that normally receive modest rainfall can get several times their annual average in just a few months, triggering rapid vegetation growth and disrupting marine food chains as nutrient-rich cold water gets displaced.
The opposite pattern, La Niña, intensifies the cold currents and can make the garúa season cooler and drier than usual. These swings mean that “average” climate data only tells part of the story. Year-to-year conditions in the Galápagos can vary far more than you would expect for an equatorial location, and the wildlife has evolved to ride out those extremes.