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 Saturday 03 Jan 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
16.5° C
(Which is 1.4°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: 0.2m 9s primary swell from a South-southwest direction and 0.1m 5s secondary swell from a Southwest direction (forecast issued at 02:00am January 03). The wind direction is predicted to be cross-offshore.
| Time (JST) & Date | Wave Height | Wave Period |
|---|---|---|
| Morning (03 Jan) | 0.5ft (0.2m) | 9s |
| Afternoon (03 Jan) | 0.5ft (0.1m) | 9s |
| Evening (03 Jan) | 0.5ft (0.1m) | 8s |
Table - waves today at Rock Island. (Swell directed towards the surf break)
Updates in hr min s Forecast update imminent
Saturday 03 | Sunday 04 | Monday 05 | ||||||||||||||||||||||
| 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 | 5 | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 4 | 8 | 8 | 6 | 4 | 7 | 6 | 6 | 6 | 6 | 8 |
Wave (?)Graph  | ||||||||||||||||||||||||
 kJ (?) | 14 | 2 | 8 | 8 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 6 | 26 | 8 | 6 | 114 | 175 | 38 | 80 | 104 | 31 |
Wind (km/h) | ||||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | off | cross- off | cross- off | cross- on | cross- on | on | cross- on | off | off | off | glass | on | cross- on | cross- on | cross | cross- off | cross | cross- on | cross | cross | cross- on | off | off | off |
High Tide / height (m) | 5:49AM 1.35 | 3:28PM 1.43 | 6:26AM 1.38 | 4:15PM 1.44 | 7:00AM 1.39 | 5:02PM 1.45 | ||||||||||||||||||
Low Tide / height (m) | 10:18PM -0.00 | 10:28AM 1.04 | 11:01PM -0.06 | 11:13AM 1.01 | 11:41PM -0.08 | 11:55AM 0.97 | ||||||||||||||||||
Saturday 03 | Sunday 04 | Monday 05 | ||||||||||||||||||||||
| Sunrise | - | - | - | 6:50 | - | - | - | - | - | - | - | 6:50 | - | - | - | - | - | - | - | 6:50 | - | - | - | - |
| Sunset | - | - | - | - | - | 4:40 | - | - | - | - | - | - | - | 4:40 | - | - | - | - | - | - | - | 4:42 | - | - |
 |  | |  | | | | | | | |  | | | |  | | | | | | |  | | |
Rain (mm) | 1 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Temp. °C | 4 | 4 | 5 | 6 | 7 | 8 | 9 | 9 | 7 | 6 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 8 | 8 | 8 | 9 | 11 | 10 | 7 |
| Feels °C (?) | -2 | -1 | 1 | 2 | 3 | 2 | 4 | 5 | 0 | 0 | 3 | 4 | 4 | 5 | 6 | 5 | 4 | 4 | 4 | 5 | 5 | 6 | 1 | -4 |
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
Latest Updates
Nazare Big Wave Challenge Gets Yellow Alert, Could Run Saturday in Giant Waves
70-foot plus waves predicted for Portuguese big wave tow surfing competition.
Buy Less, Surf More This Black Friday
Surf-forecast is providing a free, all-access pass to our premium features and 12-day forecasts all weekend.
Quiksilver Teams Up With PrimaLoft® For World’s First Thermal Layering System for a Wetsuit.
Previously used in our snow jackets for mountain conditions, PrimaLoft® technology is making its debut in the surf industry. The aim is to bring mountain-grade warmth to the waves.
Read more
Discover more articles and updates in the Greenroom.
FREE! Surf-Forecast.com widget for your website
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.
Nearest