Rock Island Surf Forecast and Surf Reports

(Kanagawa, Japan)

Forecast
- Hourly Forecast
- 16 Day Forecast
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Weather State
Spot Information

Rock Island Surf Guide

Rock Island in Kanagawa and Chiba is an exposed reef break that has pretty consitent surf Offshore winds blow from the north northeast with some shelter here from southeast winds. Windswells are much more typical than groudswells and the ideal wave angle is from the south. There is a left hand reef break. Good surf at all stages of the tide. Sometimes crowded. Submerged rocks are a hazard.

Rock Island Spot Info

Type:	Rating:	Reliability:	Todays Sea Temp*:
Reef	2	fairly consistent	20.3°C*ocean temperature recorded from satellite

Surfing Rock Island:

The best conditions reported for surf at Rock Island occur when a South swell combines with an offshore wind direction from the North-northeast.

Hourly Forecast

16 Day Forecast

What's the best time of year to surf Rock Island (for consistent clean waves)?

octoberBest Season: autumn

The best time of year for surfing Rock Island with consistent clean waves (rideable swell with light / offshore winds) is during Autumn and most often the month of October. Clean surfable waves are typically found 11% of the time in October while 12% of the time it tends to be blown out. For the remaining 77% of the time it is considered too small by most surfers but may still be OK for beginners and groms at times.

clean

11%

Surfable waves that hold up well for longer rides in prevailing cross-offshore, offshore or light wind conditions.

blown out

12%

Surfable sized waves that are of poorer quality due to prevailing onshore, cross-onshore or windy conditions (may be preferable for kitesurfing).

too small

77%

Waves usually considered too small for good surf. Some wave-magnet breaks may still work though if conditions are right (on occasion).

Explore Rock Island Location Map

Interactive Rock Island surf break location map. View information about nearby surf breaks, their wave consistency and rating compared to other spots in the region. Current swell conditions from local buoys are shown along with live wind speed and direction from nearby weather stations. Click icons on the map for more detail. The closest passenger airport to Rock Island is Tokyo International Airport (HND) in Japan, 35 km (22 miles) away (directly). The second nearest airport to Rock Island is Yokota Ab Airport (OKO), also in Japan, 54 km (34 miles) away.

Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)

Please note that some surf spot locations are approximate to protect their exact location while others are not shown at close zoom level.

Rock Island Surf Forecasts:

Hourly Forecast

16 Day Forecast

Todays Surf Summary
Thursday, 7 May 2026, 14:44 Local Time

m, °C	Thursday 07
ft, °F	12PM	3PM	6PM	9PM
Wave (m)	ESE	ESE	SSE	SSE
Period (s)	10	10	6	6
Wind (km/h)
Wind State	on	on	on	on

Tides at Rock Island

Current tide and informaton

For Sinzyuku Wan (Zusi), Kanagawa, Japan, 2 km from Rock Island.

Next High Water: 10:01pm | 1.22m

Next Low Water: 02:34am | 0.99m

NEXT	IS AT (local time)	remaining
high tide
low tide

Rock Island Sea Temperature

The water temperature (20.3 °C) at Rock Island is warm and the air temperature should feel similar (windchill forecast 19.0 °C). If the sun does come out as forecast, it should feel warm enough to surf in a shorty or a summer wetsuit.

Today, many surfers would wear a shorty.

Current Temp*: 20.3°C*ocean temperature recorded from satellite