Mareta seasonal overview
Best Surf Season (October - March)
The heart of the North Atlantic storm track delivers its most powerful offerings to Mareta during these six months. Average swell heights consistently top 2.0m – peaking near 2.4m in December and January – with dominant long-period energy (12-13s) pushing in from the NW and NNW. While those westerly quadrants are not the direct south swells the beach loves, the sheer size and period often wrap nicely into the south-facing bay, creating punchy, rippable waves in the 1.5-2.5m range. Offshore wind from N, NNE, NW and NNW blows a respectable 25-33% of the time, especially in October (33%) and November (28%), cleaning up the faces. Low-pressure systems rolling off the US East Coast re-intensify near the Azores, sending serial swells to the Algarve. When a south swell aligns with a light northerly wind – that’s the magic window for peak Mareta.
Fair Surf Season (April & September)
These transitional months offer a balanced mix. April sees average swell still at 1.9m with an 11.1s period, though NW-NNW flows dominate the swell window. Wind is ideal 24% of the time, and the combo of solid background swell and occasional spring southerly lows can fire up the spot. September is the standout fair month: average swell is only 1.5m, but the average period jumps to 10.4s, and a peak 35% of the time the wind swings offshore – the highest all year. The ocean is still warm, and the autumnal ramp-up begins, offering clean, mid-range waves that are perfect for groveling and carving.
Low Surf Season (May - August)
Summer settles in with a vengeance. From May through August, average swell heights linger around 1.4-1.6m and period drops to 8-10s – a mix of short-period windswell and small NW background pulses. The dominant wind pattern becomes strong NNW trades (often over 20-30kph), which blow offshore but the swell is too small and weak to produce quality waves. Mareta becomes a micro-swell spot, with the majority of waves falling into the 0.5-1.5m range – fun-size at best, often groveling. Wind ideal percentages hover between 20-25%, and when the rare south swell makes an appearance, it’s often accompanied by onshore southerly winds. Patience and a log are the summer tools.
Loading chart...
Conditions at Mareta in September
September: The Magic Return
September is the golden month at Mareta. Average swell rises to 1.5m and period jumps to 10.4s – the first real groundswell of the autumn. NW (47.1%) and NNW (25.5%) still dominate, but there’s a meaningful increase in WNW (14.3%) and even some W (3.8%) and WSW (1.8%) swell. The key metric: wind is ideal 35% of the time – the highest all year. NNW winds are still common (32.6%), but lighter N winds (18.6%) and a good spread of calmer conditions mean more clean waves. The longer period allows refracted swell to wrap into Mareta with more energy, producing rippable 1-1.5m waves and occasional 1.5-2m sets. The window for south swells is opening; though they remain under 1% total, a few September storms can spin up a south pulse. This is the month when you can ditch the winter suit and score fun, clean waves with offshore winds.
Average Spot conditions at Mareta in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Mareta during September. 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 Mareta for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Mareta for September. 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 Mareta.
