Conditions at Spiekeroog in September
September: The Autumn Transition Ignites
September is where Spiekeroog starts to wake up. Average swell height rises to about 4ft (1.2m), the period stretches to 5.9s, and the ideal wind percentage climbs to 15%, the highest figure of the year alongside October. The wave direction data show a textbook northwesterly swell regime: NW at 15.4%, WNW at 13.6%, W at 12.6% and NNW at 12.0%, with WSW adding another 9.0%. This delivers a mix of short-period windswell and the first real swell from autumn lows, producing more 3-5ft (1-1.5m) and 5-6ft (1.5-1.8m) days than the summer months. Winds are shiftier, but the offshore SSE/S/SSW/SW quadrant is common enough that clean sessions are no longer rare. Water temp is still a friendly 17.2°C, air temps average 15.9°C, and the top-shelf combination of warm water and building northwest swell makes September a genuine shoulder-season standout.
Average Spot conditions at Spiekeroog in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Spiekeroog 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 Spiekeroog for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Spiekeroog 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 Spiekeroog.