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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 2 am Wednesday 13 May 2026 JSTForecast update in hr min s Forecast update imminent
Rock Island surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.
Today's Rock Island sea temperature is
20.1° C
(Which is normal for this time of year)How big are the waves at Rock Island today?
The current surf forecast for Rock Island at 8AM is: 0.6m 9s primary swell from a Southeast direction and 0.1m 9s secondary swell from a South direction (forecast issued at 02:00am May 13). The wind direction is predicted to be offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (13 May) | 2ft (0.6m) | 9s |
| Afternoon (13 May) | 1.5ft (0.5m) | 9s |
| Evening (13 May) | 1.5ft (0.4m) | 9s |
Table - waves today at Rock Island. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Short Range ForecastLight rain (total 6mm), mostly falling on Wed night. Warm (max 21°C on Wed morning, min 15°C on Thu night). Wind will be generally light. | ||||||||||||||||||||||||
Wednesday 13 | Thursday 14 | Friday 15 | ||||||||||||||||||||||
12 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 12 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 12 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | |
Swell Height Map |    |    |    | |||||||||||||||||||||
SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 10 | SE 10 | SE 10 | ESE 10 | ESE 10 | ESE 10 | ESE 10 | SE 10 | ESE 11 | SSE 6 | SSE 6 | SSE 7 | SSE 6 | SE 8 | SE 8 | ESE 8 | |
51 | 50 | 49 | 50 | 41 | 41 | 31 | 29 | 34 | 33 | 34 | 19 | 9 | 10 | 9 | 27 | 11 | 5 | 5 | 6 | 5 | 13 | 11 | 6 | |
Wind (km/h) | ||||||||||||||||||||||||
glassy | glassy | off | cross-off | glassy | cross-on | on | on | glassy | off | off | cross-off | cross-off | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | glassy | on | on | on | |
High Tide | 2:10AM1.25m | 2:50PM1.17m | 2:40AM1.28m | 3:50PM1.25m | 3:10AM1.32m | 4:42PM1.32m | ||||||||||||||||||
Low Tide | 8:37AM0.48m | 8:38PM0.60m | 9:17AM0.32m | 9:25PM0.66m | 9:56AM0.17m | |||||||||||||||||||
 | |  | | |  |  |  |  |  |  | | |  | |  | | | | | | | | | |
 | — | 4:39 | — | — | — | — | — | — | — | 4:39 | — | — | — | — | — | — | — | 4:37 | — | — | — | — | — | — |
 | — | — | — | — | — | — | 6:36 | — | — | — | — | — | — | — | 6:37 | — | — | — | — | — | — | — | 6:37 | — |
— | — | — | — | — | — | — | 1 | — | 1 | 1 | 1 | 1 | 1 | — | — | — | — | — | — | — | — | — | — | |
Temp °C | 18 | 18 | 17 | 19 | 21 | 21 | 20 | 20 | 19 | 18 | 18 | 18 | 20 | 21 | 20 | 17 | 16 | 15 | 15 | 16 | 19 | 19 | 19 | 18 |
19 | 18 | 16 | 18 | 21 | 18 | 18 | 20 | 19 | 17 | 17 | 16 | 19 | 20 | 20 | 14 | 13 | 12 | 12 | 14 | 19 | 16 | 17 | 18 | |
Swell 1 Height (m) Direction Period (s) | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | SE 10 | SE 10 | SE 10 | ESE 10 | SSE 8 | SSE 7 | SSE 7 | SE 10 | SE 6 | SSE 6 | SSE 6 | SSE 7 | SSE 6 | SE 8 | SE 8 | ESE 8 |
 kJ | 51 | 50 | 49 | 50 | 41 | 41 | 31 | 29 | 34 | 33 | 34 | 19 | 6 | 5 | 5 | 27 | 7 | 4 | 3 | 5 | 4 | 11 | 11 | 6 |
Swell 2 Height (m) Direction Period (s) | — | — | S 9 | S 9 | — | — | SE 11 | ESE 11 | SE 11 | SE 10 | SE 10 | SSE 8 | ESE 10 | ESE 10 | SE 11 | E 9 | ESE 11 | SE 11 | SE 9 | SE 11 | SE 10 | SE 12 | SE 11 | SE 11 |
| kJ | — | — | 2 | 1 | — | — | 5 | 12 | 5 | 4 | 4 | 6 | 9 | 10 | 4 | 2 | 11 | 5 | 3 | 5 | 4 | 5 | 5 | 5 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | SE 11 | S 8 | — | S 7 | SE 10 | SE 10 | SE 10 | ESE 10 | S 7 | SE 8 | SE 8 | SE 11 | SE 12 | SE 12 | SSE 11 | S 7 | S 7 |
| kJ | — | — | — | — | — | — | — | 4 | 1 | — | 1 | 4 | 4 | 4 | 9 | 1 | 3 | 3 | 5 | 6 | 5 | 13 | 1 | 1 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | S 3 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SSE 3 | SSE 3 |
| kJ | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 2 | 1 |
Nearest Offshore or Glassy | ||||||||||||||||||||||||
Distance (km) | 0 | 0 | 0 | 0 | 16 | 64 | 51 | 16 | 16 | 16 | 38 | 38 | 38 | 16 | 38 | 38 | 51 | 38 | 51 | 16 | 16 | 64 | 64 | 51 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||||||
Header Global | ||||||||||||||||||||||||
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