Using Surf-Forecast’s Historical Surf Data To Find The Most Consistent Waves On Earth
Using our statistical data for 7000 spots dating back to 2006, we can find those waves that break the most, with the best winds.
Surf Forecasts:
Rock Island surfForecast / Kanagawa / Japan
48hr Weather and Surf, issued 2 am Tuesday 30 Dec 2025 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
17.1° C
(Which is 1.2°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 7AM is: 1.3m 5s primary swell from a West-southwest direction and 0.6m 5s secondary swell from a Southwest direction, 0.1m 7s secondary swell from a Southeast direction (forecast issued at 02:00am December 30). The wind direction is predicted to be cross-shore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (30 Dec) | 4.5ft (1.3m) | 5s |
| Afternoon (30 Dec) | 4ft (1.2m) | 5s |
| Evening (30 Dec) | 4.5ft (1.4m) | 6s |
Table - waves today at Rock Island. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Tuesday 30 | Wednesday 31 | Thursday 01 | ||||||||||||||||||||||
| 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 | 6 PM | 9 PM | |
Rating (10 max) | ||||||||||||||||||||||||
Swell Height Map |    |    |    | |||||||||||||||||||||
| Wave Height (m) & direction (?) | — | |||||||||||||||||||||||
| Period(s) (?) | 5 | 6 | 5 | 5 | 5 | 5 | 6 | 6 | 6 | 6 | 6 | 5 | 5 | 5 | 6 | 6 | 5 | 5 | 5 | 15 | 10 | 14 | - | 4 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 45 | 44 | 88 | 92 | 28 | 69 | 110 | 135 | 26 | 13 | 8 | 5 | 2 | 5 | 8 | 12 | 5 | 3 | 2 | 4 | 2 | 4 | 0 | 1 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- on | cross | cross | cross | cross | off | glass | off | off | cross- off | off | off | glass | cross | off | off | off | off | off | off | off | off | off | off |
High Tide / height (m) | 1:29AM 1.08 | 12:23PM 1.32 | 3:01AM 1.14 | 1:07PM 1.34 | 4:11AM 1.22 | 1:51PM 1.37 | ||||||||||||||||||
Low Tide / height (m) | 6:18AM 0.85 | 7:50PM 0.34 | 7:29AM 0.95 | 8:44PM 0.21 | 8:30AM 1.01 | |||||||||||||||||||
Tuesday 30 | Wednesday 31 | Thursday 01 | ||||||||||||||||||||||
| Sunrise | - | - | - | 6:48 | - | - | - | - | - | - | - | 6:50 | - | - | - | - | - | - | - | 6:50 | - | - | - | - |
| Sunset | - | - | - | - | - | 4:37 | - | - | - | - | - | - | - | 4:37 | - | - | - | - | - | - | - | 4:38 | - | - |
 | | |  |  | |  |  | | | | |  | | | | | | | | | | | | |
Rain (mm) | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 12 | 11 | 10 | 10 | 12 | 13 | 13 | 13 | 11 | 10 | 9 | 8 | 10 | 11 | 11 | 11 | 8 | 7 | 6 | 6 | 6 | 8 | 8 | 8 |
| Feels °C (?) | 4 | 6 | 6 | 6 | 9 | 9 | 10 | 10 | 6 | 5 | 4 | 3 | 7 | 8 | 8 | 7 | 0 | 0 | -1 | -1 | 0 | 3 | 4 | 4 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Rock Island surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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