Conditions at Costa Nova in September
September: First Autumn Pulse
September is when Costa Nova starts to come alive again. Average swell rises to 1.6m (5ft), period climbs to 10.4s, and the swell direction is heavily weighted toward NW (39.4 per cent) with NNW (22.2 per cent) and WNW (21.8 per cent) filling in the corners. There are now more genuine groundswell pulses mixing with the fading summer windswell, offering the best combination of size and reliability since spring.
Ideal wind also improves, jumping to 26 per cent as the NNW trade wind (33.8 per cent) begins to moderate and E/SE offshore flows become more frequent. With water temperature still warm at 17.8°C and air averages of 19.8°C, September delivers classic autumn surf: increasingly punchy west-northwest swell with an occasional glassy, offshore morning. Rain begins to return (1.78mm/day), but so does the surf quality.
Average Spot conditions at Costa Nova in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Costa Nova 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 Costa Nova for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Costa Nova 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 Costa Nova.