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.

January: Deep Winter Power

January sits at the heart of the North Atlantic storm track, delivering the highest average period of the year at 12.7 seconds and a solid 1.6m average height. The predominant swell direction is from the NNW, accounting for 30% of all observations, followed by NNE (20%) and N (14%). These swells arrive with plenty of energy – over 20% of waves are in the 1.5-2.5m range, making for punchy, long-period surf. However, the wind is a double-edged sword. While 8% of the time the wind blows from the ideal S, SSW, or SW quadrant, the vast majority (over 80%) of wind comes from the onshore NE, NNE, and N directions. The most common wind is from the NE at 23.5%, often howling at 20-30 kph. This means that clean, offshore conditions are a rare treat, usually associated with a low pressure system passing to the north drawing in southern winds. When those align with a NNW swell, Playa de San Juan offers powerful, lined-up waves. But expect mostly choppy, wind-affected conditions. Keep the swell period high on your priority list – longer period waves will hold up better in the onshore breeze.