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.

December in Grumari offers fairly consistent surf conditions with an average swell height of 1.3m and a solid period of 9.4s, indicating good energy in the waves. The swell is predominantly from the E, ESE, SE, SSE, and S directions, with a notable portion (around 40%) delivering waves in the 1-2.5m range, ideal for intermediate to advanced surfers. The S and SE swells, in particular, bring the largest waves (up to 2.5m+), but these are relatively rare. Wind conditions are less favorable, with only 24% of days featuring ideal offshore or light cross-shore winds (typically NE or ENE). The rest of the time, winds tend to be onshore (SE to SSW), which can create choppy conditions, especially in the afternoons. Early mornings often provide the cleanest waves. Overall, December can deliver fun, punchy waves, but patience and timing are key to scoring the best sessions.