Ohama - surf spot statistics

Ohama Beach in Japan is primarily windswell-driven, with ground swells playing a minor role throughout most of the year. The best surfing conditions typically occur from July to November when ground swell contribution increases slightly, peaking in August at 29%. However, even during these months, windswell remains dominant. Swell size averages a modest 1.1m to 1.4m year-round, with the largest waves seen from December to March (1.4m–1.5m). Unfortunately, wind conditions are generally poor, with bad winds (onshore/cross-shore) prevailing 75–83% of the time across all months. The least unfavorable winds occur from June to August, particularly in July and August when good wind probability peaks at 23–25%. Early winter (December-January) offers slightly larger swells but suffers from consistently bad winds (80%). Late summer (August) presents the best compromise—marginally higher ground swell influence and slightly better wind odds, despite the small average wave size. Surfers should prioritize July–September for relatively cleaner conditions, though expectations should be tempered given the spot’s reliance on windswell and frequent onshore flow. Overall, Ohama is a low-consistency break with no truly elite months, requiring patience and flexibility to score decent sessions.

August at Ohama delivers relatively small but consistent surf, with an average swell height of 1.1m and a decent period of 9.4s, offering rideable waves most days. The dominant swell directions are from the ESE to SSW, with the highest frequency in the 0.5-1m range, while larger swells (1.5-2.5m) are less common but present, mainly from the S-SW quadrant. Wind conditions are variable, but only 25% of the time are truly ideal (typically light offshore or cross-shore), as the prevailing winds often come from the SW to WSW at 10-30kph, which can create choppy conditions. Expect the best sessions when winds align from the NE to ENE, though these are rarer. Overall, August provides small to medium waves with occasional clean windows, better suited for longboarding or relaxed surfing, but watch for those SW wind days where conditions may deteriorate.