Playa de San Juan - surf spot statistics

Best Surf Season (October - March)

The North Atlantic winter storms fire up from October through March, delivering consistent, long-period swell to Playa de San Juan. With the beach facing NNE, the most reliable swell directions come from the NNW, N, NNE, and NE, which together dominate the swell window during these months. Average wave heights range from 1.3m to 1.7m with periods averaging 10.6 to 12.7 seconds – often in the powerful long-period range. Critically, these months also see the highest frequency of offshore winds from the S, SSW, and SW, especially in December (12% ideal) and January (8%). When a low pressure system over the Bay of Biscay or a strong Atlantic storm sends NNW swell and the wind clocks around to the south, the points and beachbreaks at San Juan light up with punchy, rippable waves. However, the dominant wind pattern is still from the NNE (onshore), so patience is key – waiting for those rare but rewarding south wind windows.

Fair Surf Season (April, May, September)

The transition months of April, May, and September offer a mix of fading winter swell and rising summer conditions. Average wave heights dip slightly (1.2-1.5m) and periods moderate (9.1-10.6s). Swell direction remains mostly from the north quadrants, but the percentage of ideal offshore wind drops to 3-6%. April still packs a punch with occasional NNE swell in the 1.5-2m range and a 10.6s average period, but the increasing incidence of onshore NE trade winds often spoils the shape. May sees a significant drop in wave quality as the wind becomes almost exclusively onshore from the N and NNE (over 70% of the time). September marks the beginning of the autumn transition: swell periods lengthen to 9.5s and the first hints of southern wind return, but still only 4% ideal conditions. These months require a sharp eye on synoptic charts – you might score a clean, glassy session when a weak low pushes south winds over the region.

Low Surf Season (June, July, August)

The summer months are the leanest time for surfing at Playa de San Juan. Wave heights average just 1.2-1.4m with short periods of 7.3-8.1 seconds, resulting in weak, windswell-driven surf. The swell direction is almost exclusively from the N and NNE, which would be optimal if not for the prevailing wind. Unfortunately, onshore winds from the N and NNE dominate with a vengeance – in July and August, ideal offshore wind is effectively 0%, and the wind blows from the north sector over 90% of the time. This creates a constant battle of choppy, onshore conditions that make waves close out. Occasionally a distant southern hemisphere swell or a rare thermal gradient can produce a light SSW breeze, but such events are extremely rare. For the dedicated surfer, summer is best spent on alternative activities or chasing the few early morning windows before the sea breeze kicks in. The surf is small, weak, and mostly unsurfable – a true low season.

September: The Autumn Awakening

September is the turning point, as the surf begins to stir. Average height holds at 1.2m, but the period lengthens to 9.5s – a sign of returning swell quality. Swell directions are more balanced: N (30.5%), NNE (31.9%), and NNW (31.1%). Wave heights are mostly under 1.5m (over 70%), but there are glimpses of 1.5-2m from NNE (8.5%). Ideal wind improves to 4% – still low, but a step up from summer. NNE wind dominates at 50.3%, with N at 23.2%. The first frontal systems of the autumn can bring a south wind change, and when they do, the small but longer-period NNW swell can produce clean, fun waves. September is a month of anticipation – the base is being built for the winter season. Keep the board waxed and watch for those early-season lows.