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.

August at Grumari offers solid surf conditions with an average swell height of 1.6m and a decent 10.5s period, providing consistent, well-shaped waves. The swell predominantly arrives from the E, ESE, SE, SSE, and S, with the strongest contributions coming from the south (S direction), where waves frequently reach 1.5-2.5m—ideal for intermediate to advanced surfers. Smaller days (0.5-1.5m) are common from the SE and SSE, offering more forgiving conditions. Wind conditions are less favorable overall, with only 20% of days seeing ideal offshore or light winds. The predominant winds come from the NE to ENE at 10-30kph, which can create choppy conditions, while onshore SW and WSW winds occasionally disrupt sessions. For the best surf, aim for days when winds shift SSE or S with lighter speeds, coinciding with the stronger south swells. While not a high-frequency wind window, when it aligns, Grumari can deliver clean, powerful waves with good shape and energy.