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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 8 am Saturday 25 Apr 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
19.3° C
(Which is slightly warmer than usual)How big are the waves at Rock Island today?
The current surf forecast for Rock Island at 4PM is: 0.4m 7s primary swell from a South-southeast direction and 0.1m 11s secondary swell from a East direction (forecast issued at 08:00am April 25). The wind direction is predicted to be cross-shore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (25 Apr) | 1.5ft (0.4m) | 8s |
| Afternoon (25 Apr) | 1.5ft (0.4m) | 7s |
| Evening (25 Apr) | 1.5ft (0.4m) | 6s |
Table - waves today at Rock Island. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Short Range ForecastHeavy rain (total 28mm), heaviest during Sun night. Very mild (max 17°C on Sun afternoon, min 13°C on Sat night). Winds increasing (light winds from the SW on Sun morning, strong winds from the N by Mon morning). | ||||||||||||||||||||||||
Saturday 25 | Sunday 26 | Monday 27 | Tue 28 | |||||||||||||||||||||
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 | 12 AM | 3 AM | |
Swell Height Map |    |    |    |    | ||||||||||||||||||||
S 8 | S 8 | S 8 | SSE 7 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SSE 6 | SE 6 | SE 7 | SE 7 | S 7 | S 7 | S 7 | SSW 7 | |
30 | 19 | 18 | 18 | 8 | 8 | 12 | 8 | 9 | 8 | 9 | 9 | 9 | 9 | 9 | 10 | 15 | 19 | 22 | 17 | 15 | 25 | 26 | 17 | |
Wind (km/h) | ||||||||||||||||||||||||
cross-off | cross-off | cross-off | cross-off | cross | cross | cross-off | cross-off | cross-off | cross-off | glassy | on | cross-on | cross | cross-off | off | off | off | off | off | off | cross-on | on | on | |
High Tide | 9:04AM1.13m | 1:11AM1.16m | 10:58AM1.05m | 1:56AM1.18m | 12:57PM1.06m | 2:30AM1.21m | ||||||||||||||||||
Low Tide | 4:39AM1.00m | 5:12PM0.29m | 6:36AM0.92m | 6:29PM0.36m | 7:48AM0.79m | 7:39PM0.41m | ||||||||||||||||||
 |  | | | |  | | |  | | | | |  | |  |  |  | |  | | |  | | |
 | 4:58 | — | — | — | — | — | — | 4:56 | — | — | — | — | — | — | — | 4:56 | — | — | — | — | — | — | — | 4:54 |
 | — | — | — | — | 6:21 | — | — | — | — | — | — | — | 6:22 | — | — | — | — | — | — | — | 6:22 | — | — | 6:23 |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 6 | 11 | 10 | — | 1 | — | — | — | — | |
Temp °C | 13 | 14 | 15 | 16 | 15 | 14 | 13 | 13 | 13 | 14 | 16 | 17 | 17 | 16 | 16 | 15 | 14 | 14 | 15 | 14 | 15 | 15 | 15 | 16 |
8 | 9 | 10 | 12 | 10 | 10 | 10 | 11 | 10 | 12 | 14 | 14 | 14 | 14 | 14 | 11 | 7 | 6 | 8 | 9 | 14 | 13 | 13 | 14 | |
Swell 1 Height (m) Direction Period (s) | S 8 | S 8 | S 8 | SSE 7 | S 7 | S 7 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SE 6 | SSE 6 | SE 6 | SE 7 | SE 7 | S 7 | S 7 | S 7 | SSW 7 |
 kJ | 30 | 19 | 18 | 18 | 4 | 4 | 9 | 8 | 9 | 8 | 9 | 9 | 9 | 9 | 9 | 10 | 15 | 19 | 22 | 17 | 15 | 25 | 26 | 17 |
Swell 2 Height (m) Direction Period (s) | SE 12 | E 12 | SE 12 | E 11 | E 11 | — | S 7 | S 7 | S 7 | S 7 | S 7 | S 7 | E 13 | — | E 13 | — | — | — | — | S 7 | SE 7 | SE 7 | SE 6 | SE 6 |
| kJ | 5 | 3 | 5 | 2 | 2 | — | 1 | 1 | 1 | 1 | 1 | 1 | 3 | — | 3 | — | — | — | — | 8 | 12 | 7 | 7 | 6 |
Swell 3 Height (m) Direction Period (s) | SW 8 | E 8 | E 8 | — | — | SE 11 | — | — | — | — | — | — | S 7 | S 6 | — | S 16 | S 16 | S 16 | S 16 | — | — | — | — | — |
| kJ | 18 | 10 | 5 | — | — | 5 | — | — | — | — | — | — | 1 | 1 | — | 5 | 5 | 5 | 5 | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | NE 3 | NE 3 | ENE 3 | — | SE 6 | SE 6 | ESE 6 | — | — | — | — | — | — | — | — | — | NE 3 | NNE 3 | NNE 3 | NNE 3 | — | — | — | — |
| kJ | 2 | 2 | 1 | — | 8 | 8 | 12 | — | — | — | — | — | — | — | — | — | 2 | 7 | 4 | 1 | — | — | — | — |
Nearest Offshore or Glassy | ||||||||||||||||||||||||
Distance (km) | 470 | 470 | 51 | 64 | 755 | 64 | 64 | 38 | 38 | 51 | 16 | 572 | 38 | 38 | 488 | 488 | 54 | 145 | 90 | 61 | 16 | 18 | 18 | 76 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||||||
Header Global | ||||||||||||||||||||||||
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