Conditions at Sao Juliao in May
May: Shoulder-Season Lull
May marks the real transition into the summer pattern. Average swell height drops to 1.7m (5.6ft), and the period shortens to 9.9s, pushing the surf into the average-to-punchy category. The swell source is increasingly NNW (31.5%) and NW (30.5%), with WNW (17.4%) still contributing, but the energy is less consistent and more wind-driven. The wind picture is the bigger issue: NNW winds blow 36.5% of the time and N winds another 12.7%, while offshore ENE/E/ESE/SE wind totals only around 9% of the time. Those rare offshore mornings can produce clean, waist-to-shoulder-high lines, but most of the month you'll be deciphering cross-onshore conditions. Water temperature rises to 16.5°C, air temps average 16.7°C, and precipitation drops to 1.48 mm/day. It's a good month for a smaller board and low expectations.
Average Spot conditions at Sao Juliao in May
Swell history for May
Wind history for May
Swell quality
Analyze the groundswell consistency at Sao Juliao during May. 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 Sao Juliao for your next trip in May.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Sao Juliao for May. 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 Sao Juliao.