Conditions at Praia da Vieira in September
September: The First Roar of Autumn
September is when Praia da Vieira starts waking up. Average swell height rebounds to 5ft (1.5m) and the average period jumps to 10.5s, as the developing North Atlantic storm track sends more organized WNW and NW groundswell toward the Portuguese coast. The dominant directions remain NW (43.6%) and WNW (22.7%), but the main improvement is that a greater share of the energy sits in the 3-7ft (1-2m) range and the period is noticeably longer. Ideal offshore wind also improves to 18%, though NNW still dominates 37.5% of the time. This is a tricky transition month: you can catch glassy, warm-water autumn surf with water temps of 18.2°C, or you can still find summer-style chop. The first rains arrive too, with 1.45 mm/day measured precipitation. Keep the summer suit handy, but start charging that step-up once the first distant low appears on the forecast maps.
Average Spot conditions at Praia da Vieira in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Praia da Vieira 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 Praia da Vieira for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Praia da Vieira 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 Praia da Vieira.