When To Go · Destination Guide
Mantas, turtles, and a stingless jellyfish lake in a remote Coral Triangle corner of Borneo
Updated Dec 13, 2025 • 12 sources
When to go
Derawan is equatorial and warm yearround, with water often around 28°C.
Best overall window
Drier weather, steadier seas, and more consistent visibility. Water stays around 28°C.
Outside that window
Wetter monsoon months can bring heavier rain and choppier crossings, especially when winds build to 20 km/h or more.
Start with the overall answer, then switch only when scuba, freedive, snorkel, or topside timing changes the trip in a meaningful way.
The overall row stays visible so you can compare it against the currently selected scope.
| Scope | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Overall | Overall - Jan: Tradeoffs | Overall - Feb: Tradeoffs | Overall - Mar: Tradeoffs | Overall - Apr: Good | Overall - May: Best | Overall - Jun: Best | Overall - Jul: Best | Overall - Aug: Best | Overall - Sep: Best | Overall - Oct: Good | Overall - Nov: Tradeoffs | Overall - Dec: Tradeoffs |
These do not replace the overall planner. Use them only if a specific animal or event is driving your trip dates.
Manta rays around Sangalaki
Best for Scuba, Snorkel, Freedive
Year-round
Mantas are a headline feature of Sangalaki.
Green turtle nesting and hatchlings
Best for Snorkel, Scuba, Topside
Apr to Sep
Turtles are common yearround, but nesting activity often peaks in the middle of the year on key beaches.
Kakaban lake swim conditions
Best for Snorkel, Topside
May to Sep
Drier months usually mean easier logistics and more comfortable lake swims.
Whale shark chances on Berau coast (bagan platforms)
Best for Snorkel, Freedive, Scuba
Mar to Jun
Some itineraries add a mainland coast day for possible whale shark encounters around fishing platforms.
Built from climate references, access rules, and destination operators. Wildlife timing and route flexibility can shift year to year.