Short answer: September is in the cool season: days around 24.3°C, nights around 19.6°C, sea 21.5°C and choppy seas. It is the quietest month of the year for visitors. Wildlife highlights: sea lion pupping season, galápagos fur seal breeding season, galápagos penguins: active fishing.
Weather in September
- 24.3°Caverage high, Puerto Ayora
- 19.6°Caverage low
- 21.5°Csea temperature (coolest month)
- 11 mmtypical rain over 3.1 rainy days (middling)
The cool season runs roughly June to November. September is drier at the coast, often grey and misty in the highlands, with southeasterly winds that make the sea choppier. The upwelling of cold, nutrient-rich water is what makes the marine life so active.
Compared with August (21.5°C sea) and October (21.7°C), September is cooling down.
What the animals are doing in September
- Sea lion pupping season (pups present year-round)All islands; Playa Baquerizo / La Lobería (San Cristóbal), North Seymour, Mosquera
Wikipedia: breeding May to January. - Galápagos fur seal breeding seasonSantiago (Puerto Egas), Genovesa, western Isabela, Fernandina
Wikipedia: mid-August to mid-November, peak late September to early October. - Galápagos penguins: active fishing (May), courtship peak (September)Bartolomé; Isabela and Fernandina west coast
GCT: penguins very active at Bartolomé in May and at courtship peak in September. - Whale sharks at Darwin Island (adult, mostly pregnant females)Darwin Island (liveaboard dive/snorkel only)
Peer-reviewed six-year study: presence tracked sea surface temperature inversely, concentrated July-December (about 207 sightings Jul-Dec vs 4 Jan-Jun, from a blog summary of the paper). - Hammerhead sharks most abundant in the cool seasonDarwin and Wolf (liveaboard only); Kicker Rock sometimes (secondary)
CDF-led study compared March (warm) with August (cold): hammerhead biomass about 5 t/ha in the warm season vs 21 t/ha in the cold season. - Humpback and blue whales in the Marine ReserveOpen water; Santa Fé sighting 2005
Springer chapter (Denkinger and colleagues) reports presence June-November. - Flamingo egg layingLagoons: Villamil and Punta Moreno (Isabela), Las Bachas and Garrapatero (Santa Cruz), Punta Cormorán (Floreana)
Tindle et al. - Flightless cormorant breeding seasonFernandina, northern and western Isabela
Wikipedia summary: April to October. - Cool-season upwelling: marine life most active, best snorkellingWestern and central islands
GCT: June is start of cooler air and water; July cold nutrient-rich water makes marine life more active; October nutrients inshore make snorkelling great.
Where to find each animal and how likely you are to see it: wildlife bingo card.
Boats and seasickness in September
Sea conditions are usually choppy. Plan the long crossings (Santa Cruz to Isabela, Bartolomé, Española) for the morning boats, take a seasickness tablet before boarding and sit at the back. The seasickness meter rates every month and boat.
How busy is September?
September is the quietest month of the year for visitors. The park counted 290,404 visitors in 2025, with demand peaks in March–April and July–August and the low point in September. Last-minute availability is usually fine outside the holiday weeks.
What to pack for September
- A 3 mm wetsuit or rash guard for snorkelling (most tour boats lend wetsuits; ask).
- Reef-safe sunscreen, a hat and sunglasses: the sun is strong on the equator in every month.
- A windproof layer for boat rides and the misty highlands.
- Seasickness tablets, especially this month.
Good tours for September
Kicker Rock & Beach Full-Day Tour
North Seymour: Day Tour with Wildlife Walk & Snorkeling
Tintoreras Islet: Penguins & Blue-Footed Boobies
Los Túneles: Snorkel with Sharks, Seahorses & Sea Turtles
Prices and ratings as listed in November 2026; the price at checkout is what counts. We may earn a commission at no extra cost to you. Disclosure
Questions people ask about September
Is September a good time to visit the Galápagos?
Yes. It is the cool season: the sea is around 21.5°C, days reach about 24.3°C, and the nutrient-rich water brings the most active marine life. September is the quietest month of the year for visitors.
How warm is the sea in September?
About 21.5°C at Puerto Ayora (30-year average), the coolest month of the year. Most people want a 3 mm wetsuit for long snorkels.
Does it rain in September?
Very little: a typical September brings about 11 mm over 3.1 rainy days, though the highlands are often misty.
Is the sea rough in September?
Sea conditions are usually choppy. The two-hour inter-island ferries can be bumpy; take a tablet and sit at the back.
Other months
All twelve months side by side · What a trip costs · Plan your days
Sources: Charles Darwin Foundation, NOAA, Galápagos Conservation Trust, Galápagos National Park and Governing Council, peer-reviewed research, Audubon. Every figure with its document: facts and figures.
Updated 2026-11-06. Fees, boat times and prices change, so confirm with the operator before you travel.