Conditions at Kugenuma in September
September: Typhoon Swells and Emerging North Winds
September is the pivotal transition month from the summer low toward the autumn and winter season. The average swell height stays at 0.8m, but the period remains elevated at 9.0s, reflecting a mix of typhoon-driven swells and early mid-latitude storms. S (21.0%) and SSE (20.3%) are the primary swell directions, with SE at 17.0% and SSW at 12.7%; the NE/NNE quadrant also begins to contribute more background swell. More importantly, the wind rose starts to tilt back toward winter: NNE jumps to 25.0%, NE to 14.0% and N to 7.7%, while onshore SSW and SW totals shrink. The ideal-wind frequency rises to 18%, tying with May but with much better wave quality. Rain is at its annual peak at 7.15 mm/day, a reminder of decaying typhoons and autumn fronts. Water is still warm at 25.4°C and air averages 22.0°C. For the surfer, September offers a rare combination of warm water, long-period south-southeast swell and increasing offshore wind - early-season dawn patrols can be surprisingly good.
Average Spot conditions at Kugenuma in September
Swell history for September
Wind history for September
Swell quality
Analyze the groundswell consistency at Kugenuma 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 Kugenuma for your next trip in September.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Kugenuma 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 Kugenuma.