Aterro - surf spot statistics

Aterro in Portugal offers consistent surf conditions throughout the year, but the best months for surfers typically fall between October and March. During this period, ground swell dominates, with percentages ranging from 62% in October to 89% in January, ensuring powerful and well-formed waves. The mean swell size is also most favorable, averaging between 1.3m and 1.7m, providing ideal wave heights for intermediate to advanced surfers. Wind conditions improve slightly in these months, with good wind days peaking at 43% in January and December, though offshore winds remain somewhat inconsistent. From April to September, conditions deteriorate as wind swells take over, reducing wave quality, and bad wind conditions dominate, often exceeding 70%. Swell size drops below 1.0m in summer, making it less reliable for serious surfers. While Aterro is surfable year-round, the winter and early spring months deliver the most consistent, high-quality waves with better wind alignment, making them the prime time for surfing at this spot.

September at Aterro offers decent surf conditions with a mix of smaller, manageable waves and occasional larger swells. The average swell height is 0.9m with a solid period of 10.7s, indicating well-formed, clean waves when the swell direction aligns. The best waves come from W, WNW, and NW directions, which dominate the swell distribution—particularly in the 0.5-2.5m range, with WNW being the most consistent (peaking at 25% for 0.5-1m waves). Larger swells (over 2.5m) are rare but possible. Wind conditions are critical, with only 27% of days offering ideal surf winds. Offshore winds (light ENE-E) are most favorable, while stronger N/NW winds can create chop. Mid-range swells (1-2m) with lighter winds provide the best sessions, though surfers should watch for larger W/WNW swells paired with favorable winds for more powerful waves. Overall, September is a reliable month for intermediate surfers, with the occasional clean, head-high day when conditions align.