Aterro seasonal overview
Best Surf Season (October - March)
From October through March, Aterro is at its peak. The North Atlantic storm track swings south toward Iberia, and the resulting extratropical lows fire long-period groundswell across the entire optimal swell window - WSW, W, WNW and NW. Average wave heights run 7-9ft (2.1-2.7m) with periods of 11-13 seconds, while offshore wind frequencies reach 36-48%. These are the months when the biggest, cleanest and most consistent surf lights up the west-northwest-facing sandbar.
Fair Surf Season (April - May, September)
During the shoulder months of April, May and September, conditions are more transitional. Swell heights ease to 5-6ft (1.5-1.8m), periods drop back into the 9-11 second range, and the percentage of ideal wind falls to 22-28%. These months can still produce glassy morning sessions, especially when a late-season low sends a solid W/NW swell during a light offshore flow, but do not expect the same raw power or consistency as winter.
Low Surf Season (June - August)
Summer is the flat and wind-affected season at Aterro. The Azores High locks in, the Atlantic storm track retreats to the north, and swell heights sink to 4-5ft (1.2-1.5m) with periods in the 8-9 second range. The prevailing NNW thermal wind blows almost daily, degrading the surface while NW and WNW winds add onshore push. Ideal wind percentages collapse to just 11-15%. This is grovel season, but on the right small days there can still be fun, rippable waves.