google it mate!
Dry season (March-October) is the main surf producer, when generous Indian Ocean swells can sometimes reach 12-15ft (4-5m) in June-August from a SSW- WSW direction. The main trend is the SE trades, which blow-out many exposed spots, especially from June-Sept. Unlike Bali, the trades don't blow consistently during the day, instead there are on and off windy periods. Obviously, trades gets stronger as the day progress, but sometimes thunderstorms can change wind patterns, so early and late glass-offs are common.
magicseaweed.com/Indonesia-Surf-Chart/44/Go there surfing but don't count on wind. Like the rest of the tropics.