Grupuk - surf spot statistics

Best Surf Season (December - March)

The southern shores of Lombok come alive during the heart of the Indonesian wet season. From December through March, the monsoon trough shifts northward, allowing offshore winds from the north and northwest to prevail over 30-58% of the time. This window sees a steady supply of groundswell from the south and southwest, with average wave heights holding in the fun, rippable 1-1.5m range and periods consistently above 12 seconds. The combination of clean conditions and well-defined swell makes this the prime time for Grupuk.

Fair Surf Season (November & April)

The transitional months of November and April offer a mixed bag. Swell energy remains high, with periods often exceeding 13 seconds, but the wind patterns become less reliable. In November, offshore flow from the north and west appears only about 10% of the time, while onshore southerly and easterly winds dominate. April sees a sharp drop to 25% favorable winds as the southeast trade winds begin to strengthen. Still, when a light offshore breeze aligns with a SSW groundswell, you can score some of the smoothest waves of the year.

Low Surf Season (May - October)

The dry season transforms Grupuk into a wind-dominated challenge. From May through October, the southeast trades blow relentlessly, clocking in at 15-30 kph from the ESE and SE. Ideal offshore winds from the north are virtually absent (often less than 2% occurrence). While the swell actually peaks during these months – average heights climb to 1.6-1.8m with powerful, long-period energy (14+ seconds) – the almost constant onshore wind chops up the surface, making conditions predominantly messy and difficult. Only the most sheltered corners or fleeting windows of lighter wind offer rideable waves.

March: Late Season Gem

March still offers excellent conditions, though the window of perfect winds begins to narrow (45% favorable). Swell energy shifts to a dominant SSW direction (63.6%), with average heights at 1.3m and a very long average period of 13.4s. These long-period swells produce deep-water energy that unloads with real authority on the reef. Winds are more variable, with a mix of westerly and easterly flow. Look for days when a light northwesterly breeze meets a SSW groundswell – that is when Grupuk truly shines.