Conditions at Sines in September
September: The Autumn Alarm Clock
September is where the ocean starts to wake up. Average swell height climbs slightly to 4.6ft (1.4m) and, more importantly, average period jumps to 10.6 seconds. There is more power in the water than in July or August, and the direction mix begins to broaden with NW at 55.4 percent and WNW at 21.3 percent. The first S/SW and WSW swells of the fall start to appear, giving Sines a taste of the winter setup to come. With ideal wind at 61 percent, this is the best quality-to-consistency tradeoff of the low-to-fair season. Small groundswell windows can still be punchy and clean on the south-facing sandbars.
Air temperatures are summer-like at 21.3°C, rainfall remains modest at 0.85 mm per day, and water temperature is the warmest of the year at 18.1°C. Time to start watching the Atlantic forecast again.
Average Spot conditions at Sines in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Sines 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 Sines for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Sines 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 Sines.