Choshi - surf spot statistics

Choshi, Japan, offers surfable waves year-round, but the best conditions are typically found during the winter months, from November to February. During this period, ground swell makes up a significant portion of the swell mix (32-48%), providing more consistent and cleaner waves compared to wind swell, which dominates the rest of the year. The mean swell size is also slightly larger in winter (1.6-1.8m), offering better surf potential. However, wind conditions are far from ideal, with only 24-28% of days having favorable winds—offshore or light cross-shore—while the majority of days see onshore or strong winds that can degrade wave quality. From March to October, wind swell becomes increasingly dominant, peaking from May to July (75-91% of swells), which often results in choppier, less organized waves. The swell size drops slightly (1.4-1.8m), and the chances of good winds remain low (16-22%). Late September and October can still see decent swells (1.8m) but suffer from inconsistent winds. Overall, if you're seeking the best balance of swell size and quality, late autumn to early winter (November-February) is the prime window, despite the frequent poor winds. Summer and spring months are less reliable, with smaller, wind-affected waves dominating. For dedicated surfers, patience and selective timing around wind forecasts are key to scoring good sessions in Choshi.

May in Choshi offers surfable conditions with an average swell height of 1.5m and a decent period of 8.5s, providing reasonable energy for waves. The dominant swell direction is easterly (ENE-E-ESE), contributing to the majority of waves in the 1-2m range, with occasional larger sets up to 2.5m. Wind conditions are less favorable, with only 16% of days offering ideal offshore or light cross-shore winds (predominantly from the W-NW quadrant). However, winds from the S-SSW are more common, often blowing onshore at moderate speeds (10-30kph), which can create choppy or less clean conditions. Surfers should target days with lighter winds from the west or northwest for cleaner faces, but even then, expect variable quality due to mixed swell directions. Overall, May is a fair month for intermediate surfers who can handle occasional wind-affected waves, but it’s not the most consistent or pristine season for high-performance surfing.