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.

December at Rosa offers decent surf conditions with an average swell height of 1.5m and a solid period of 8.6s, providing well-formed and manageable waves. The swell primarily arrives from the east to southeast (ENE to SSE), with the majority of waves in the 1-2m range—ideal for intermediate to advanced surfers. The ENE, E, and ESE directions contribute the largest share of rideable waves, often clean and powerful due to the favorable period. Wind conditions are mixed, with only 15% of days offering ideal offshore winds (typically light ENE or E breezes). However, stronger NNE to NE winds can create chop, especially when speeds exceed 20kph. While cross-shore or onshore winds are more frequent, early mornings often provide cleaner sessions. Overall, December delivers consistent surf with good energy, though patience with wind conditions is key. The spot handles larger swells (2m+) well, but expect fewer pristine days due to variable winds.