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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 8 pm Sunday 17 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
19.7° C
(Which is slightly cooler than normal)How big are the waves at Rock Island today?
The current surf forecast for Rock Island at 11PM is: 0.3m 8s primary swell from a Southeast direction and 0.1m 11s secondary swell from a Southeast direction (forecast issued at 08:00pm May 17). The wind direction is predicted to be cross-onshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (17 May) | - | - |
| Afternoon (17 May) | - | - |
| Evening (17 May) | 1ft (0.3m) | 8s |
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 8mm), mostly falling on Wed afternoon. Warm (max 22°C on Tue afternoon, min 18°C on Wed morning). Winds decreasing (fresh winds from the S on Tue afternoon, calm by Wed afternoon). | ||||||||||||||||||||||||
Sun 17 | Monday 18 | Tuesday 19 | Wednesday 20 | |||||||||||||||||||||
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 | 12 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | |
Swell Height Map |   |    |    |    | ||||||||||||||||||||
SE 10 | SE 8 | SE 8 | SE 8 | ESE 8 | SSE 8 | SE 10 | SE 10 | SE 10 | SE 10 | SE 7 | SSE 7 | SE 10 | SE 10 | SE 11 | S 4 | SSW 4 | SE 11 | SE 11 | SE 11 | SE 11 | SE 10 | SE 10 | SE 10 | |
17 | 10 | 11 | 10 | 7 | 6 | 17 | 16 | 16 | 16 | 12 | 10 | 16 | 29 | 18 | 27 | 31 | 29 | 29 | 29 | 29 | 28 | 27 | 26 | |
Wind (km/h) | ||||||||||||||||||||||||
on | on | cross | glassy | glassy | cross-on | on | on | on | on | on | on | on | on | on | on | on | on | on | on | on | on | on | glassy | |
High Tide | 6:15PM1.38m | 4:38AM1.42m | 7:00PM1.37m | 5:10AM1.43m | 7:46PM1.35m | 5:44AM1.42m | ||||||||||||||||||
Low Tide | 11:23PM0.86m | 11:49AM-0.09m | 11:59PM0.91m | 12:29PM-0.09m | 00:37AM0.95m | 1:09PM-0.06m | ||||||||||||||||||
 |  | | | | | | | | | | | | |  | | | | |  |  | |  | | |
 | — | — | — | 4:35 | — | — | — | — | — | — | — | 4:35 | — | — | — | — | — | — | — | 4:33 | — | — | — | — |
 | 6:38 | — | — | — | — | — | — | — | 6:39 | — | — | — | — | — | — | — | 6:40 | — | — | — | — | — | — | 6:42 |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 2 | 2 | |
Temp °C | 22 | 20 | 20 | 20 | 19 | 20 | 21 | 21 | 21 | 20 | 20 | 19 | 19 | 20 | 21 | 21 | 22 | 21 | 20 | 20 | 20 | 20 | 18 | 18 |
19 | 19 | 19 | 19 | 18 | 18 | 16 | 17 | 18 | 17 | 17 | 17 | 17 | 17 | 17 | 16 | 18 | 18 | 18 | 19 | 20 | 19 | 18 | 20 | |
Swell 1 Height (m) Direction Period (s) | SE 10 | SE 8 | SE 8 | SE 8 | ESE 8 | SSE 8 | SE 8 | SE 8 | SSE 7 | SE 7 | SSE 7 | SSE 7 | SE 10 | SE 10 | SE 11 | SE 11 | SE 11 | SE 11 | SE 11 | SSE 4 | SE 11 | SE 10 | SE 10 | SE 10 |
 kJ | 15 | 10 | 11 | 10 | 7 | 6 | 9 | 9 | 5 | 8 | 5 | 5 | 16 | 28 | 18 | 18 | 18 | 29 | 29 | 6 | 29 | 28 | 27 | 26 |
Swell 2 Height (m) Direction Period (s) | SE 10 | SE 10 | SE 12 | SE 12 | SSE 7 | ESE 8 | SE 10 | SE 10 | ESE 10 | SE 10 | ESE 10 | ESE 10 | SSE 7 | ESE 9 | ESE 9 | E 10 | SE 4 | — | — | SE 11 | S 4 | — | S 9 | S 9 |
| kJ | 17 | 4 | 5 | 5 | 5 | 6 | 4 | 4 | 10 | 4 | 10 | 10 | 4 | 29 | 16 | 8 | 1 | — | — | 29 | 3 | — | 2 | 2 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 7 | SSE 7 | — | — | — | — | — | — | — | — | SSE 5 | — | — | S 9 |
| kJ | — | — | — | — | 4 | 4 | 17 | 16 | 16 | 16 | 12 | 9 | — | — | — | — | — | — | — | — | 2 | — | — | 2 |
Wind waves Height (m) Direction Period (s) | S 2 | S 3 | — | — | — | — | — | S 3 | S 3 | S 3 | SSW 3 | SSW 3 | SSW 3 | SSW 3 | S 4 | S 4 | SSW 4 | SSW 4 | SSW 4 | SW 4 | S 4 | SSW 4 | SSW 4 | S 4 |
| kJ | 1 | 1 | — | — | — | — | — | 4 | 8 | 6 | 3 | 2 | 2 | 4 | 13 | 27 | 31 | 25 | 13 | 5 | 9 | 6 | 5 | 5 |
Nearest Offshore or Glassy | ||||||||||||||||||||||||
Distance (km) | 16 | 92 | 55 | 51 | 38 | 16 | 16 | 16 | 76 | 77 | 77 | 90 | 90 | 38 | 38 | 90 | 92 | 77 | 77 | 38 | 38 | 38 | 18 | 18 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||||||
Header Global | ||||||||||||||||||||||||
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