Conditions at Oniguchi in September
September: The Clean Rebound
September is the turning point. Average swell height is 1.1m (3.5ft), and the average period climbs to 8.4s-the highest of the year. The swell direction is still dominated by the east: E is 24.4%, ESE is 15.8%, SE is 10.3% and ENE is 9.2%, while the SW sector contributes a small but important 13.8%. The wind improves dramatically, with ideal offshore flow present 53% of the time. ENE winds are 14.1%, E winds are 13.9%, ESE is 10.2% and NNW adds 10.1%. Air temperature is 26.5°C, water temperature remains warm at 27.9°C, and precipitation is 8.84 mm/day. This is when the first autumn frontal systems begin to mix with lingering typhoon energy, producing cleaner conditions and more push. E/NE swells are not perfect for the SW-facing beach, but the surface is often glassy and the better W/SW pulses can reward those who are patient.
Average Spot conditions at Oniguchi in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Oniguchi 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 Oniguchi for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Oniguchi 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 Oniguchi.