Conditions at Grupuk in September
September: Endless SSW Groundswell, Still Windblown
September keeps the dry-season engine running. Average swell height is 1.7m (5.5ft), period is a long 14.2s, and SSW direction peaks at 84% of the wave energy - one of the most directionally consistent months of the year. Waves in the 1.5-2m and 2-2.5m classes are plentiful, so this is a serious groundswell month. But the wind is still locked in from the SE/SSE, with ideal conditions only 1% of the time. Grupuk will see a lot of swollen but ropy, wind-affected faces. Only a major weakening of the trades could unite the swell and clean conditions.
Average Spot conditions at Grupuk in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Grupuk during September. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at Grupuk for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Grupuk for September. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at Grupuk.