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.

August: Slight Summer Shift

August is marginally better than July, but still firmly in the low season. Average height is 1.3m, period 7.7s, and ideal wind 0%. Swell direction is still dominated by NNE (58.6%) and N (29%), with a slight increase in NNW (12%). Most waves are in the 0.5-1.5m range, but there is a small percentage of 1.5-2m (3.8% from N, 22% from NNE). The wind remains overwhelmingly onshore: NNE at 63.5% and N at 27.2%. Offshore 0% means no consistent south wind. However, the late summer can see occasional distant hurricane swells that bypass the wind – these might bring longer-period, cleaner waves for a day or two. Otherwise, it's small, weak, and onshore. August requires patience and a good surf forecast to catch any anomaly.