San Blas - surf spot statistics

Best Surf Season (November - February & July - August)

The heart of the surf calendar at San Blas delivers a classic combo of consistent, long-period SSW swell and reliable offshore winds from the north quadrant. In winter, the North Pacific storm track fires up, sending powerful groundswells marching toward the Central American coast with average wave periods between 12 and 13 seconds and heights in the fun-to-good 1m range. Simultaneously, the strengthening of the North American high-pressure system funnels steady offshore breezes from N/NE, keeping the wave faces clean and groomed. During July and August, a secondary peak emerges as the tropical trade winds relax, allowing a higher percentage of light offshore winds while the swell from the Southern Hemisphere remains strong, pushing average heights above 1.3m and periods above 13s. These months offer the best mix of power and shape for a rippable, walled-up wave.

Fair Surf Season (March - April & September - October)

Transitional months bring a trade-off: the swell builds in height and period, often reaching peak averages above 1.2m and periods of 14s, but the offshore wind reliability begins to fade. March and April see the offshore wind percentage drop to 47% and 40% respectively, as the region starts to feel the influence of the Intertropical Convergence Zone (ITCZ), which can introduce more onshore components from the south and southwest. September and October are similar: the swell remains solid, with SSW directions dominating over 73% of the time, but the window of clean offshore wind narrows to around 51-54%. Morning glassy conditions are common, but afternoon sea breezes can quickly mess things up. Still, when the right combination emerges – a good S-SSW groundswell coupled with a north wind – the waves are long, powerful, and well-shaped.

Low Surf Season (May - June)

The low point of the year at San Blas is less about lack of swell and more about wind consistency. May and June still produce solid SSW groundswell with average heights rising to 1.4m and periods holding at 14s, but the percentage of ideal offshore wind plummets to 42% and 53% respectively. The ITCZ sits overhead, bringing frequent light onshore winds from the south and southwest, which degrade wave quality and create bumpy, less organized surf. Additionally, the increased tropical moisture can lead to overcast skies and occasional thunderstorms. While the swell is far from flat, the onshore bias means you'll often be scratching for clean peaks. Look for early mornings or days when a weak cold front pushes north winds back down – those are the jewels in an otherwise fickle period.

September: Transitional Power

September is a month of mixed signals: average swell height remains at a solid 1.4m, period drops slightly to 13.0s, but wind ideal percentage dips to 51%. The swell direction broadens a bit, with SSW at 73.1% and SW swell increasing to 16.2% – indicating more westerly tracking systems. This can produce longer, more drawn-out waves with steep drop-ins. Wind conditions become fickle: offshore flow from N/NE quadrants totals about 31% (NNE 7.8%, NE 8.9%, ENE 9.6%, N 4.6%), but onshore winds from S/SSW/SW make up around 18%. The challenge is finding clean windows, but when the wind cooperates, the long-period swell lines are incredibly powerful. September is a month for the dedicated surfer who can read the weather and pounce on the right morning or evening session.