Conditions at Katahama in July
July: Typhoon Season Begins, Winds Still Onshore
July sees the onset of the typhoon season in the western Pacific, and the swell period nudges up to 8.3s as more organized swells rotate around the subtropical high. The directional distribution shows a strong SSW component (28.1%) and S (18.6%), but also SE (14.5%) and SSE (13.9%) - the optimal directions are present around 39.3% of the time. However, the wind regime is dominated by WSW (22.9%) and SW (15.1%), both of which are onshore at Katahama. Offshore flow from the W/NW sector is almost non-existent (8.5%). The result is a month of warm, humid, bumpy conditions, with the occasional typhoon swell delivering bigger waves but usually accompanied by wild winds. If a typhoon tracks such that the swell comes out of the ESE/SE while the wind turns offshore in the aftermath, the bay can light up with powerful, clean surf - a rare treat in July. Water temps reach 24.0°C, air averages 25.4°C, and rainfall is high at 7.85 mm/day.
Average Spot conditions at Katahama in July
Swell history for July
Wind history for July
Swell quality
Analyze the groundswell consistency at Katahama during July. 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 Katahama for your next trip in July.
Ground swell
Ground swell by size
Wind conditions
Evaluate the wind and swell alignment at Katahama for July. 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 Katahama.