Grumari - surf spot statistics

Grumari, Brazil, offers surfable conditions year-round, but the best months for consistent surf are typically from April to July. During this period, ground swell frequency peaks (51-58%), providing cleaner, more organized waves, while wind swell remains moderate (41-52%). Mean swell size also increases to around 1.5-1.6m, offering better wave power. Wind conditions during these months are not ideal but manageable, with 25-30% of days having favorable offshore or light winds, though onshore winds dominate. The worst wind conditions occur from August to November, where unfavorable winds exceed 80% of days, often causing choppy surf despite decent swell. From December to March, wind swell dominates (63-69%), resulting in less consistent wave quality, though still surfable, especially when ground swell contributes. September stands out with the largest mean swell (1.7m) but suffers from the highest percentage of bad winds (85%). For the best balance of swell size, ground swell dominance, and less terrible wind conditions, May and June are the top months—offering a solid mix of wave energy and occasional clean conditions. Early mornings or late evenings may provide better surf due to lighter winds. Overall, intermediate to advanced surfers will find the most rewarding sessions in late autumn and early winter (April-July), while other months require patience with wind and swell variability.

In September, Grumari offers decent surf conditions with an average swell height of 1.7m and a solid 10.2s period, indicating consistent, well-formed waves. The swell direction is predominantly from the S to SSE (peaking at 1.5–2.5m), which often produces clean, rideable waves at this beach break. However, ENE to E swells, though less frequent, can also contribute, especially in the 1–2m range. Wind conditions are challenging, with only 15% of days providing ideal offshore or light cross-shore winds (typically from the W to NW). The majority of winds are ENE to ESE at 10–30kph, which can create onshore chop, particularly during stronger easterlies. Surfers should prioritize early sessions when winds are lighter. Overall, September delivers rideable waves regularly, but wind quality is hit-or-miss, requiring selective timing for optimal conditions. Larger swells (2m+) from the S/SSE provide the best opportunities for advanced surfers.