Surf forecastStatisticsHistorical report

Choshi seasonal overview

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.

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Conditions at Choshi in March

March: Spring Transition

March sees a slight shift: average height inches up to 1.8m, but period drops to 9.6s. Swell from ENE (17.2%) and E (11.0%) gains ground, while NE (18.5%) still dominates. Offshore wind frequency falls to 32%, with clean N and NW winds competing with onshore SSW and SW breezes. The 1-1.5m and 1.5-2m waves are common, offering rippable conditions when the wind cooperates. March is a transitional month - the swell angle starts to improve, but the wind consistency takes a step back, making a timing play essential.

Average Spot conditions at Choshi in March

Swell history for March

0 - 0.5
0.5 - 1
1 - 1.5
1.5 - 2.0
2.0 - 2.5
> 2.5 m

Wind history for March

0 - 10
10 - 20
20 - 30
30 - 40
40 - 50
> 50 km/h

Swell quality

Analyze the groundswell consistency at Choshi during March. 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 Choshi for your next trip in March.

Ground swell

Ground swell by size

Wind conditions

Evaluate the wind and swell alignment at Choshi for March. 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 Choshi.

Swell with good wind

Swell with good wind by size