April to October is the main season for Labuan Bajo and Komodo: drier weather, calmer seas, and easier boat schedules. July and August are busiest, so book boats and dives ahead.
The wet season, especially December to March, brings greener hills and fewer visitors but rougher seas. Some boat trips still run, though itineraries change more often. Manta encounters can be excellent in the wet months, but do not plan a tight schedule around a single boat day.