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Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 8 pm Friday 10 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
14.9° C
(Which is 2.9°C colder than average for this time of year)How big are the waves at Rock Island today?
The current surf forecast for Rock Island at 5AM is: 2.3m 9s primary swell from a South-southwest direction and 1.5m 9s secondary swell from a South direction, 0.1m 11s secondary swell from a Southeast direction (forecast issued at 08:00pm April 10). The wind direction is predicted to be cross-onshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (11 Apr) | 5.5ft (1.7m) | 9s |
| Afternoon (11 Apr) | 3.5ft (1.0m) | 8s |
| Evening (11 Apr) | 8ft (2.5m) | 7s |
Table - waves today at Rock Island. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Fri 10 | Saturday 11 | Sunday 12 | Monday 13 | |||||||||||||||||||||
| 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | 6 PM | 9 PM | 0 AM | 3 AM | 6 AM | 9 AM | 12 PM | 3 PM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |   |    |    |    | ||||||||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||||
| Period(s) (?) | 8 | 8 | 9 | 9 | 8 | 9 | 8 | 8 | 8 | 7 | 7 | 8 | 8 | 8 | 7 | 3 | 12 | 6 | 6 | 6 | 11 | 11 | 11 | 11 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 612 | 702 | 724 | 859 | 290 | 463 | 157 | 124 | 260 | 627 | 127 | 64 | 49 | 24 | 8 | 5 | 13 | 18 | 26 | 24 | 19 | 19 | 19 | 19 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | on | on | on | on | cross- on | off | cross- off | cross- on | on | cross- off | off | off | off | cross- off | on | on | on | on | on | on | on | on | on | on |
High Tide / height (m) | 1:18AM 1.11 | 9:53AM 1.10 | 2:15AM 1.15 | 12:03PM 1.06 | 2:50AM 1.19 | 1:47PM 1.11 | ||||||||||||||||||
Low Tide / height (m) | 4:52PM 0.24 | 5:41AM 1.01 | 6:14PM 0.29 | 7:35AM 0.91 | 7:31PM 0.32 | 8:32AM 0.77 | ||||||||||||||||||
Fri 10 | Saturday 11 | Sunday 12 | Monday 13 | |||||||||||||||||||||
| Sunrise | - | - | - | - | 5:16 | - | - | - | - | - | - | - | 5:13 | - | - | - | - | - | - | - | 5:13 | - | - | - |
| Sunset | 6:08 | - | - | - | - | - | - | - | 6:09 | - | - | - | - | - | - | - | 6:10 | - | - | - | - | - | - | - |
 |  |  | |  | | | | | | | |  | | | | |  |  | | | | | | |
Rain (mm) | 1 | 11 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 18 | 19 | 18 | 18 | 17 | 18 | 20 | 20 | 20 | 20 | 18 | 15 | 13 | 14 | 14 | 15 | 15 | 15 | 15 | 15 | 15 | 16 | 17 | 18 |
| Feels °C (?) | 13 | 15 | 13 | 15 | 16 | 18 | 20 | 18 | 17 | 18 | 13 | 8 | 4 | 9 | 9 | 9 | 10 | 11 | 12 | 12 | 13 | 14 | 14 | 15 |
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Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
FREE! Surf-Forecast.com widget for your website
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