San Blas seasonal overview
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.
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Conditions at San Blas in December
December: Peak Season Excellence
December culminates the year with the highest wind ideal percentage of all: 66%. Average swell height is 1.0m with period 12.2s, indicating a consistent, long-period groundswell. Swell direction is led by SSW (63.4%) and S (22.7%), delivering well-lined-up waves that break with authority. The wind is overwhelmingly offshore, with NNE (32.2%) and N (15.6%) dominating the direction chart. These winds are often moderate (10-20kph) which is perfect for holding up steep faces without creating too much chop. The rare onshore flow from S/SSW is only about 10% combined. December is the classic holiday season for surfers – expect reliable, clean waves that are perfect for intermediate to advanced surfers. The consistent quality makes San Blas a go-to spot during this peak month.
Average Spot conditions at San Blas in December
Swell history for December
Wind history for December
Swell quality
Analyze the groundswell consistency at San Blas during December. Based on historical data, there is a % probability of groundswell occurring this month. The chart below provides a detailed breakdown of the average wave height distribution, offering deep insights into the swell quality and surf potential you can expect at San Blas for your next trip in December.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at San Blas for December. Our analysis shows that favorable offshore or side-shore winds coincide with surfable swell approximately % of the time. The accompanying graph illustrates the average size distribution of waves during these optimal wind windows at San Blas.
