Belongas Bay - surf spot statistics

Best Surf Season (December - March)

The heart of the Indonesian wet season delivers the most consistent combination of quality swell and favorable offshore winds at Belongas Bay. The Indian Ocean comes alive as the monsoon trough shifts south, sending powerful, long-period groundswells from the SSW and SW directly into the south-facing bay. Average wave heights sit in the 1.5-1.6m range with periods averaging 12-13 seconds, providing solid, rippable waves. Crucially, the wind blows from the north quadrant (N, NNE, NNW) 48-59% of the time, grooming the swell into clean, hollow lines. This is the window for peak Belongas – expect pumping, firing conditions during these months.

Fair Surf Season (April & November)

April and November represent the transitional shoulders, where the monsoon winds are shifting. Swell energy remains excellent, with April averaging 1.5m at 13.8s and November at 1.5m at 13.2s, both heavily dominated by SSW and SW swells. However, the offshore wind consistency drops to 30% in April and just 10% in November as the trade winds start to build or fade. You'll find more variable conditions: mornings can still offer clean offshore texture before the onshore seabreeze kicks in, or a passing storm can deliver a brief window of perfection.

Low Surf Season (May - October)

The dry season is synonymous with the Southeast trade winds, which blow relentlessly across the region. While this period sees the largest average swell heights (1.7m to 2.0m) and longest periods (14-14.4s), the wind direction is predominantly from the ESE, SE, and SSE – directly onshore for Belongas Bay. Ideal offshore wind percentages plummet to single digits (1-12%). As a result, the waves are typically blown out, choppy, and messy. Surfable windows are rare and brief, often occurring during a southerly wind shift or a break in the trades. Only the most dedicated and patient surfers should consider this season for Belongas.

May: Swell Peaks, Wind Quality Dives

Swell energy continues to climb in May, averaging 1.7m with a long 14.1s period. The swell direction spreads slightly, with SSW (56%) still dominant but S (29%) and SSE (6%) adding more south energy. This is a powerful, long-period pulse. Unfortunately, the wind ideal percentage plummets to just 12%. The Southeast trades lock in, with ESE (38%) and SE (37%) becoming the primary winds – directly onshore for Belongas. Surf sessions become a battle against chop. Only rare days with a north shift or light winds offer clean waves.