Conditions at Oniguchi in April
April: East Swell Takes Over
April is a true transition month. The average swell height drops to 1.1m (3.5ft), and the average period remains 7.2s. The swell direction changes dramatically: E and ESE together account for 27.6% of all swell, with SE adding another 7.7%. The old winter NW/NNW pattern still lingers at 17.1% combined, and the optimal SW sector improves to around 16%, but the overall size is smaller and less consistent. Ideal wind drops to 44% as the wind rose becomes more variable, with ESE at 9.4%, E at 9.2%, NW at 15.6% and NNW at 15.0%. Air temperature climbs to 18.0°C, water temperature is 19.6°C, and precipitation rises to 7.01 mm/day. Surfers should pick their windows carefully in April, looking for NW groundswell with offshore N/NW winds before the summer pattern locks in.
Average Spot conditions at Oniguchi in April
Swell history for April
Wind history for April
Swell quality
Analyze the groundswell consistency at Oniguchi during April. 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 April.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Oniguchi for April. 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.