Conditions at Zarautz in September
September: The Autumn Fuse is Lit
September is the first month that genuinely hints at the coming winter. Average swell height climbs to 4ft (1.3m) and the period lengthens to 10.4s, so the wave quality improves noticeably over the summer slop. Direction remains heavily NW - 53.5% NW, 21.0% WNW and 14.5% NNW - and there is now a meaningful share of 1-2m (3-6ft) groundswell. It is not yet consistent, but the storm track is starting to wake up.
Wind is still the limiting factor. NNW and WNW breezes remain frequent, and the S/SSW offshore flow accounts for just 11.9% of observations, giving ideal conditions 32% of the time. However, late September can deliver classic shoulder-season surf: a fresh NW groundswell, a south wind under a building high, water still warm at 20.9°C, and air temps around 19.0°C. The first proper surf trip windows of the autumn open up this month, and the promise of firing winter waves begins to fill the air.
Average Spot conditions at Zarautz in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Zarautz 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 Zarautz for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Zarautz 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 Zarautz.