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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 2 am Sunday 31 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
20.8° C
(Which is slightly cooler than normal)How big are the waves at Rock Island today (31 May):
- Morning surf: Morning surf (31 May, local time) - 1ft (0.3m), 15s period with S swell.
- Afternoon surf: Afternoon surf (31 May, local time) - 1.5ft (0.5m), 13s period with S swell.
- Evening surf: Evening surf (31 May, local time) - 2ft (0.6m), 12s period with S swell.
The current surf forecast for Rock Island at 11AM is: 0.3m 14s primary swell from a South direction and 0.3m 6s secondary swell from a South-southeast direction (forecast issued at 02:00am May 31). The wind direction is predicted to be glassy.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (31 May) | 1ft (0.3m) | 15s |
| Afternoon (31 May) | 1.5ft (0.5m) | 13s |
| Evening (31 May) | 2ft (0.6m) | 12s |
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 Tue night. Warm (max 27°C on Sun afternoon, min 19°C on Tue night). Winds increasing (calm on Sun morning, fresh winds from the SSW by Mon night). | ||||||||||||||||||||||||
Sunday 31 | Monday 1 | Tuesday 2 | ||||||||||||||||||||||
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 |    |    |    | |||||||||||||||||||||
SSE 6 | SSE 6 | S 15 | S 15 | S 13 | S 13 | S 12 | S 12 | S 12 | S 11 | S 11 | S 11 | S 11 | S 10 | S 13 | SSW 13 | SSW 13 | SSW 13 | SSW 13 | SSW 13 | SSW 12 | SSW 12 | SSW 13 | SSW 12 | |
8 | 7 | 18 | 39 | 31 | 81 | 108 | 100 | 98 | 125 | 119 | 86 | 85 | 156 | 163 | 168 | 238 | 246 | 238 | 227 | 145 | 161 | 209 | 196 | |
Wind (km/h) | ||||||||||||||||||||||||
cross-on | glassy | off | off | glassy | cross-on | on | on | on | cross-on | cross-on | cross-on | cross-on | on | on | on | on | on | on | on | on | on | on | on | |
High Tide | 3:31AM1.41m | 5:55PM1.37m | 4:05AM1.44m | 6:40PM1.39m | 4:40AM1.45m | 7:23PM1.39m | ||||||||||||||||||
Low Tide | 10:12PM0.88m | 10:43AM-0.02m | 10:53PM0.93m | 11:23AM-0.08m | 11:32PM0.97m | 12:03PM-0.10m | ||||||||||||||||||
 | |  | | | |  |  | | |  | | | | | | | | | | | | | | |
 | — | 4:28 | — | — | — | — | — | — | — | 4:28 | — | — | — | — | — | — | — | 4:28 | — | — | — | — | — | — |
 | — | — | — | — | — | — | 6:50 | — | — | — | — | — | — | — | 6:50 | — | — | — | — | — | — | — | 6:51 | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Temp °C | 22 | 22 | 21 | 23 | 25 | 27 | 24 | 22 | 21 | 21 | 20 | 22 | 23 | 22 | 21 | 21 | 21 | 20 | 21 | 21 | 21 | 21 | 21 | 21 |
23 | 23 | 20 | 22 | 25 | 26 | 22 | 19 | 19 | 22 | 20 | 23 | 23 | 20 | 18 | 17 | 18 | 17 | 19 | 18 | 18 | 19 | 19 | 20 | |
Swell 1 Height (m) Direction Period (s) | SSW 4 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | S 13 | S 12 | S 12 | S 12 | S 6 | S 6 | S 11 | S 11 | SSW 14 | S 13 | SSW 13 | SSW 13 | SSW 13 | SSW 13 | SSW 13 | SSW 12 | SSW 12 | SSW 13 | SSW 12 |
 kJ | 4 | 7 | 7 | 7 | 6 | 81 | 108 | 100 | 98 | 58 | 33 | 86 | 85 | 105 | 163 | 168 | 238 | 246 | 238 | 227 | 145 | 161 | 209 | 196 |
Swell 2 Height (m) Direction Period (s) | SSE 6 | SSW 4 | SSW 4 | S 15 | S 13 | SSE 6 | SE 12 | SSW 14 | SE 12 | S 11 | S 11 | S 6 | SSW 16 | SE 11 | SSW 15 | SSW 15 | SE 11 | SE 11 | SE 11 | SE 11 | SW 14 | SW 14 | SE 11 | SE 11 |
| kJ | 8 | 2 | 1 | 39 | 31 | 6 | 6 | 39 | 5 | 125 | 119 | 22 | 53 | 5 | 89 | 86 | 5 | 5 | 5 | 5 | 91 | 99 | 5 | 5 |
Swell 3 Height (m) Direction Period (s) | SE 11 | SE 11 | S 15 | SE 12 | SSW 15 | SE 12 | SSW 14 | SE 12 | ESE 10 | S 18 | SSW 17 | SSW 14 | SSW 14 | ESE 10 | SE 11 | SE 11 | E 9 | SE 11 | E 9 | SE 11 | SE 11 | SE 11 | SW 18 | SW 18 |
| kJ | 5 | 5 | 18 | 6 | 22 | 6 | 63 | 6 | 9 | 6 | 29 | 39 | 36 | 18 | 5 | 5 | 6 | 30 | 6 | 20 | 5 | 5 | 50 | 12 |
Wind waves Height (m) Direction Period (s) | SW 3 | — | — | — | — | — | S 3 | SSW 5 | SSW 6 | — | SW 6 | SSW 5 | S 5 | S 10 | S 4 | S 4 | S 3 | SSW 3 | SSW 3 | SSW 3 | S 3 | S 4 | S 4 | S 4 |
| kJ | 4 | — | — | — | — | — | 4 | 69 | 87 | — | 33 | 19 | 13 | 156 | 16 | 10 | 5 | 6 | 4 | 3 | 3 | 13 | 22 | 30 |
Nearest Offshore or Glassy | ||||||||||||||||||||||||
Distance (km) | 18 | 16 | 16 | 0 | 0 | 6 | 76 | 518 | 27 | 10 | 12 | 18 | 18 | 77 | 92 | 27 | 27 | 27 | 14 | 77 | 77 | 77 | 77 | 14 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||||||
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