Conditions at Foz in September
September: The First Strong Signal of Autumn
September is where the season starts to turn back on. Average swell heights tick up to 1.1m (3.6ft) and periods stretch to 10.1s, with the first real long-period groundswells of the new Atlantic season. NW (35%) and NNW (35%) continue to dominate the wave rose, and 75% of the total swell comes through the favorable NW-to-W window. Wind is still a mixed bag: ENE (21%) and NE (16%) hold on to the summer pattern, but SSW and SW have strengthened to 19% combined, lifting the ideal surf percentage to 32%. Water temps remain warm at 19.4°C, air averages 16.7°C, and rainfall is still modest at 1.9mm/day. With the ocean starting to wake up, September is a transition month that often produces the best combination of warm water and a fresh, clean groundswell.
Average Spot conditions at Foz in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Foz 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 Foz for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Foz 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 Foz.