Choshi - surf spot statistics

Best Surf Season (October - March)

The winter months deliver the most consistent offshore wind conditions thanks to the strengthening Siberian High. Average wind ideal rates climb to 40-47% from November through January, with winter storms spinning up across the North Pacific and sending long-period groundswell. While the dominant swell direction is from the northeast, the south-facing beaches of Choshi still pick up a mix of ENE and E swell that can produce punchy, rideable waves. The average wave period hovers around 9.5-9.9s, offering solid power. Still, when a storm tracks favorably, we can see SSW or SW swell with offshore N winds - that is when the stars align for Choshi's best waves.

Fair Surf Season (April, September)

April sees a shift in the dominant swell window to more easterly and southeasterly directions, increasing the potential for good wave angles. September is a transition month where tropical systems in the Western Pacific can fire up SSE and S swells, often with light offshore winds early in the season. These months average 1.6-1.7m wave heights with periods around 9.2-9.4s, providing fun-sized conditions for the dedicated surfer, though the wind ideal percentage drops to 26-35%.

Low Surf Season (May - August)

Summer in Choshi is dominated by the East China Sea monsoon pattern, bringing persistent S to SW winds that are mostly onshore. While the swell direction turns favorable toward SE and S, the wind quality deteriorates significantly, with ideal wind rates dropping to 25-31%. Wave heights average 1.2-1.4m and periods shorten to 8.6-8.9s, resulting in small, choppy conditions. Occasional typhoon swells can break the monotony, but they are usually accompanied by strong onshore winds and dangerous surf.

May: Monsoon Onset

May sees the monsoon pattern lock in: average wave height drops to 1.4m and period to 8.8s. The dominant swell direction shifts to ESE (22.7%) and E (18.5%), which are better angles for Choshi, but the wind quality plummets to 25% ideal. Onshore SSW (16.9%), S (10.9%), and SSE (8.0%) winds are frequent, creating bumpy conditions. Most waves are in the 1-1.5m range, offering groveling potential. Look for early morning offshores or wait for a typhoon swell to break the pattern.