Indonesia's dive seasons are shaped by two monsoons: the southeast monsoon, which brings dry weather to most of the country from roughly May to October, and the northwest monsoon, which brings rain and wind from roughly November to April. But because the archipelago is so vast, the monsoons affect each region differently, and a few destinations run on the opposite schedule entirely.

Here is what that means for each of Indonesia's major diving regions.

Bali and Nusa Penida: April to November

Bali's dry season from April to November brings the calmest seas and best visibility to sites like Tulamben's USAT Liberty wreck, Amed, and Menjangan Island. The headline event is the mola mola season around Nusa Penida, which runs from about July to October, when cold upwellings draw oceanic sunfish up to the cleaning stations. Manta rays at Manta Point are a year-round attraction. Diving continues through the rainy season too; you just trade some visibility for quieter sites.

Photo by Sebastian Pena Lambarri

Komodo National Park: Year-Round, Best April to November

Komodo's main season runs from April to November, when the northern sites like Batu Bolong and Castle Rock enjoy calm conditions and superb visibility. During the rainy season from roughly December to February, attention shifts south: plankton blooms reduce visibility but bring feeding manta rays in numbers, making it a favorite window for manta lovers. Read our full Komodo diving guide for site-by-site details.

Photo by Chase Rief

Raja Ampat: October to April

Raja Ampat runs opposite to most of Indonesia. Its prime season is October to April, when seas are calm and liveaboards concentrate in the region; this is also the best window for reef mantas at sites like Manta Sandy. From May to September, the southeast monsoon brings wind and chop, and many operators reposition elsewhere. If Raja Ampat is your dream trip, plan around its season first, then fit the rest of your itinerary in. Our first-timer's guide to Raja Ampat covers the details.

Photo by sutirta budiman

Gili Islands and Lombok: Year-Round, Best May to October

The Gilis offer easy, turtle-rich diving all year, with the dry months from May to October providing the most settled conditions. The rainy season is generally still very diveable, with short storms rather than washed-out weeks. See our Gili Islands diving guide for the best sites.

North Sulawesi, Bunaken and Lembeh: Year-Round, Best March to October

Bunaken's wall diving is at its best during the dry season from March to October, when visibility regularly exceeds 25 meters. The Lembeh Strait is sheltered and productive in every month, with many guides rating July to November as the peak critter season thanks to cooler water. The two combine beautifully in a single trip; see our guides to Bunaken and Lembeh.

Pulau Weh, Sumatra: Year-Round

Out at Indonesia's western tip, Pulau Weh is diveable in every season. Sites ring the island, so operators can nearly always find sheltered conditions regardless of wind direction.

Quick Answer: So When Should You Go?

• July to October: Mola mola at Nusa Penida, peak Komodo season, prime Lembeh critters

• October to April: Raja Ampat at its best, with calm seas and manta aggregations

• December to February: Feeding mantas in south Komodo; Raja Ampat in full swing

• April to June: Shoulder season sweet spot: good conditions in Bali, Komodo, and Sulawesi with fewer crowds

The honest answer to "when is the best time to dive Indonesia" is: whenever you can go. There is always a region in season. Match your dates to the table above, pick your region, then use Scubalo to compare dive centers and explore dive sites before you book.

Planning across borders? Our month-by-month guide to diving Southeast Asia zooms out to the whole region.