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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 2 am Friday 01 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
19.8° C
(Which is slightly warmer than usual)How big are the waves at Rock Island today?
The current surf forecast for Rock Island at 7AM is: 1.2m 8s primary swell from a South-southeast direction (forecast issued at 02:00am May 01). An open ocean swell of 0.3m 3s is not directed at the surf break. The wind direction is predicted to be offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (01 May) | 5ft (1.5m) | 8s |
| Afternoon (01 May) | 11ft (3.5m) | 9s |
| Evening (01 May) | 8ft (2.5m) | 8s |
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 53mm), heaviest during Fri morning. Warm (max 21°C on Sun afternoon, min 14°C on Fri morning). Mainly near gales. | ||||||||||||||||||||||||
Friday 1 | Saturday 2 | Sunday 3 | ||||||||||||||||||||||
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 6 | SSE 7 | SSE 7 | SSE 8 | S 8 | S 9 | S 9 | SSW 8 | SSW 8 | SW 10 | SSW 10 | SSW 11 | SSW 11 | SW 10 | SW 10 | SSW 9 | SSW 8 | SSW 8 | SSW 7 | SSW 6 | ESE 10 | SSW 4 | SSW 4 | SSW 5 | |
12 | 42 | 111 | 322 | 789 | 1770 | 929 | 984 | 771 | 1363 | 358 | 238 | 143 | 49 | 24 | 47 | 40 | 22 | 9 | 8 | 10 | 13 | 42 | 83 | |
Wind (km/h) | ||||||||||||||||||||||||
off | off | off | off | cross-off | glassy | on | cross-on | cross-on | cross-on | off | on | on | cross | glassy | glassy | cross-off | off | off | glassy | on | on | on | on | |
High Tide | 3:52AM1.32m | 5:05PM1.35m | 4:18AM1.35m | 5:51PM1.38m | 4:45AM1.38m | 6:36PM1.38m | ||||||||||||||||||
Low Tide | 10:05PM0.56m | 10:27AM0.16m | 10:43PM0.63m | 11:03AM0.04m | 11:18PM0.71m | 11:39AM-0.03m | ||||||||||||||||||
 | |  |  | |  |  |  | | | | | |  | |  |  | |  | | | | | | |
 | — | 4:50 | — | — | — | — | — | — | — | 4:50 | — | — | — | — | — | — | — | 4:48 | — | — | — | — | — | — |
 | — | — | — | — | — | — | 6:25 | — | — | — | — | — | — | — | 6:27 | — | — | — | — | — | — | — | 6:28 | — |
1 | 4 | 9 | 29 | 18 | 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Temp °C | 12 | 12 | 13 | 14 | 14 | 16 | 19 | 17 | 15 | 14 | 15 | 17 | 18 | 20 | 20 | 20 | 19 | 18 | 17 | 18 | 19 | 21 | 20 | 19 |
6 | 7 | 10 | 10 | 13 | 17 | 11 | 7 | 6 | 6 | 13 | 14 | 14 | 18 | 20 | 19 | 17 | 16 | 16 | 18 | 17 | 16 | 15 | 13 | |
Swell 1 Height (m) Direction Period (s) | SE 6 | SSE 7 | SSE 7 | SSE 8 | SSE 8 | S 9 | SE 9 | SE 9 | SE 9 | SSW 8 | SSW 10 | SSW 11 | SSW 11 | S 8 | SSW 7 | SSW 9 | SSW 8 | SSW 8 | SSW 7 | SSW 6 | ESE 10 | ESE 10 | ESE 10 | SE 10 |
 kJ | 12 | 42 | 111 | 322 | 404 | 916 | 350 | 123 | 90 | 453 | 358 | 238 | 143 | 28 | 16 | 47 | 40 | 22 | 9 | 8 | 10 | 10 | 10 | 4 |
Swell 2 Height (m) Direction Period (s) | — | N 3 | N 3 | — | — | — | — | — | — | — | SE 11 | SE 8 | SE 8 | SW 10 | SW 10 | SSE 8 | SE 8 | SE 8 | SSE 7 | SE 7 | S 7 | — | — | — |
| kJ | — | 4 | 1 | — | — | — | — | — | — | — | 5 | 15 | 15 | 49 | 24 | 6 | 10 | 9 | 5 | 2 | 1 | — | — | — |
Swell 3 Height (m) Direction Period (s) | SW 6 | — | — | — | — | — | — | — | — | — | SSE 8 | SE 11 | SE 11 | S 7 | SE 8 | — | — | S 7 | SE 10 | SE 10 | — | — | — | — |
| kJ | 1 | — | — | — | — | — | — | — | — | — | 11 | 5 | 5 | 17 | 11 | — | — | 4 | 4 | 4 | — | — | — | — |
Wind waves Height (m) Direction Period (s) | NNE 2 | NNE 3 | — | NE 3 | S 8 | S 9 | S 9 | SSW 8 | SSW 8 | SW 10 | — | — | — | — | — | — | — | — | — | — | SSW 6 | SSW 4 | SSW 4 | SSW 5 |
| kJ | 1 | 3 | — | 2 | 789 | 1770 | 929 | 984 | 771 | 1363 | — | — | — | — | — | — | — | — | — | — | 8 | 13 | 42 | 83 |
Nearest Offshore or Glassy | ||||||||||||||||||||||||
Distance (km) | 38 | 38 | 0 | 0 | 0 | 0 | 487 | 487 | 487 | 470 | 0 | 55 | 534 | 12 | 0 | 0 | 0 | 38 | 16 | 16 | 18 | 572 | 944 | 794 |
Best forecast wave conditions in Kanagawa | ||||||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||||||
Header Global | ||||||||||||||||||||||||
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