Rosa - surf spot statistics

Prainha, or Rosa, in Brazil is a consistent surf spot with year-round swell, primarily dominated by wind swell rather than ground swell. The best months for surfing here are generally from April to September, when ground swell percentages increase, offering better-quality waves. During this period, ground swell averages between 28% and 42%, peaking in May and June with 42%, which means more powerful and organized waves. Swell size remains relatively stable, averaging around 1.6m to 1.7m, with September seeing the largest mean swell at 1.9m. However, wind conditions are less favorable overall, with good wind days being relatively rare—typically under 26% throughout the year. The worst wind conditions occur from September to December, dropping below 15% favorable winds. Conversely, the slightly higher chance of good winds from May to June (24%–26%) makes these months more promising despite the persistent dominance of onshore winds. Outside the peak months, the high percentage of wind swell (often above 80%) creates choppier, less ideal conditions. If you prioritize wave consistency and size, target May through July; if you're willing to compromise on wind, September brings the biggest swells, though wind conditions are particularly poor. Overall, mid-year offers the best balance between swell size and quality, even though winds remain a challenge.

August at this Brazilian surf spot offers decent conditions with an average swell height of 1.7m and a solid period of 9.6s, suggesting well-formed, powerful waves. The dominant swell directions are from the east and southeast, with the largest concentration of waves (over 1.5m) coming from SSE, S, and NE sectors. Notably, S swells bring the biggest waves, with a significant portion in the 1.5-2.5m+ range, ideal for more experienced surfers. Wind conditions are less favorable, with only 18% of days providing ideal offshore or light cross-shore winds. The wind tends to blow from the N/NE at moderate to strong speeds (10-30+ kph), which can create choppy or onshore conditions, reducing wave quality. When winds align from the E/ENE, they’re lighter and more surf-friendly, but these instances are rarer. Expect a mix of overhead to head-high waves with occasional larger sets, but be prepared for inconsistent wind conditions that may require patience for clean sessions. The spot works best when S/SSE swells meet lighter easterly winds.