Surf Forecasts:
Rock Island surf forecast from 11 Jul 2026:
- Best quality surf: Monday 13 Jul, 6AM (local time) - 3.5ft (1.0m), 13s period, SSW swell with glassy winds.
- Most powerful swell: Saturday 11 Jul, 12PM (local time) - 7ft (2.1m), 17s period, SSW swell with 2,455 kJ wave energy.
- Next surfable swell (1★+): Monday 13 Jul, 6AM (local time) - 3.5ft (1.0m), 13s period with SSW swell.
Best Forecast Surf Conditions for Rock Island this week:
The surf forecast for Rock Island over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Monday (Jul 13) at 6AM. The primary swell is predicted to be 1.0m and 13s period with a secondary swell of 0.4m and 5s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Rock Island in the next 16 days are 2.1m 17s and forecast to arrive on Saturday (Jul 11) at 12PM. Winds are predicted to be onshore at the time the swell arrives.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6AM (Mon 13th Jul) | 3.5ft (1.0m) 13s |
| Best Surf | 6AM (Mon 13th Jul) | 3.5ft (1.0m) 13s |
| Most Powerful | 12PM (Sat 11th Jul) | 7ft (2.1m) 17s |
Table - best surf conditions forecast for Rock Island over the next 16 days.
Alright folks, Rusty here. Let’s get straight into it for Rock Island. It’s a reef break, exposed to the south swell, but honestly, this is shaping up to be a pretty quiet stretch. We’re looking at a long, flat period ahead.
The first real chance of a wave isn’t until Monday, July 13th. We’ve got a solid waiting game before that. The water temp is sitting at 74.8°, which is a bit colder than normal for this time of year, so you might want a thin spring suit.
Monday morning, July 13th, is the best we’ve got in the whole outlook. The swell is a clean 3 ft from the SSW with a solid 13-second period, offering a decent bit of energy (260). The wind is light and offshore from the NNE, meaning the faces will be clean. It’s small, but it’s the standout. The afternoon glass off with a 12-second period (222 combined energy) will be even cleaner, but the size stays the same. This is really the only window worth paddling out for.
After that, it drops off hard. Tuesday and Wednesday are tiny, with onshore winds making a mess of things. The rest of the first week and the entire second week are flat. We’re talking about a solid 10-day run from the 14th through to the 23rd of July where there’s nothing worth getting wet for. The energy drops into the double digits and single digits, with onshore and cross-shore winds.
There’s a tiny flicker of life around Wednesday, July 22nd, with a 2 ft swell from the ESE and a long 13-second period, but the wind is a moderate 25 km/h offshore. That’s one for the dawn patrol if you’re desperate, but the energy is low (226) and it’s marginal. For a reef break that’s only fairly consistent, this kind of blank run is pretty normal. Don’t hold your breath.
Short Range ForecastLight rain (total 3mm), mostly falling on Sat night. Warm (max 28°C on Mon afternoon, min 24°C on Sat morning). Winds decreasing (fresh winds from the S on Sat afternoon, calm by Mon morning). | Days 4-6 Weather SummaryMostly dry. Warm (max 27°C on Wed afternoon, min 25°C on Tue morning). Wind will be generally light. | ||||||||||||||||||||
Saturday 11 | Sunday 12 | Monday 13 | Tuesday 14 | Wednesday 15 | Thursday 16 | Friday 17 | |||||||||||||||
AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map |  |  |  |  |  |  |  | ||||||||||||||
Wave Height (m) Direction Period (s) | SSW 16 | SSW 17 | SSW 16 | SSW 16 | SSW 16 | SSW 14 | SSW 13 | SSW 12 | SSW 11 | SSW 11 | SSW 10 | SSW 10 | SSW 9 | SW 9 | SSW 9 | SSW 9 | S 4 | SSW 8 | SE 9 | SE 9 | SSE 8 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2368 | 2296 | 1697 | 1493 | 1040 | 487 | 249 | 206 | 140 | 91 | 59 | 38 | 35 | 21 | 16 | 7 | 12 | 7 | 12 | 20 | 89 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | on | on | cross-on | glassy | on | cross-on | cross-on | on | on | cross-on | on | on | on | on | on | cross-on | on | on |
High Tide | 4:01PM1.24m | 1:22AM1.40m | 4:55PM1.32m | 2:17AM1.43m | 5:37PM1.38m | 3:10AM1.46m | 6:12PM1.43m | 4:01AM1.49m | 6:44PM1.45m | 4:50AM1.51m | 7:13PM1.45m | 5:38AM1.50m | 7:41PM1.45m | ||||||||
Low Tide | 8:06PM1.09m | 9:13AM0.17m | 9:17PM1.11m | 10:01AM0.08m | 10:13PM1.10m | 10:45AM0.02m | 10:59PM1.06m | 11:27AM-0.00m | 11:40PM1.01m | 12:06PM0.02m | 00:20AM0.94m | 12:43PM0.07m | 00:59AM0.86m | ||||||||
 | |  |  | |  | | | | | |  |  | |  | | | | | | | |
 | 4:35 | — | — | 4:35 | — | — | 4:35 | — | — | 4:37 | — | — | 4:37 | — | — | 4:37 | — | — | 4:39 | — | — |
 | — | 6:58 | — | — | 6:58 | — | — | 6:58 | — | — | 6:57 | — | — | 6:57 | — | — | 6:55 | — | — | 6:55 | — |
mm | — | — | 2 | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 25 | 25 | 25 | 25 | 25 | 25 | 27 | 28 | 27 | 26 | 26 | 25 | 26 | 27 | 25 | 26 | 27 | 26 | 28 | 28 | 26 |
Feels °C | 24 | 23 | 24 | 28 | 26 | 28 | 31 | 30 | 30 | 29 | 28 | 27 | 29 | 29 | 26 | 27 | 28 | 29 | 30 | 30 | 29 |
Swell 1 Height (m) Direction Period (s) | SSW 16 | SSW 17 | SSW 16 | SSW 16 | SSW 16 | SSW 14 | SSW 13 | SSW 12 | SSW 11 | SSW 11 | SSW 10 | SSW 10 | SSW 9 | SW 9 | SSW 9 | SSW 9 | SE 9 | SSW 8 | SE 9 | SE 9 | SSE 8 |
| kJ | 2368 | 2296 | 1697 | 1493 | 1040 | 487 | 249 | 206 | 140 | 91 | 59 | 38 | 35 | 21 | 16 | 7 | 3 | 7 | 12 | 20 | 89 |
Swell 2 Height (m) Direction Period (s) | — | — | — | SE 10 | SE 10 | S 4 | SSW 5 | SE 10 | SE 9 | SE 9 | SE 12 | SE 10 | SE 10 | SE 10 | ESE 9 | SE 9 | SE 10 | SE 10 | SSW 8 | SSW 8 | SW 8 |
| kJ | — | — | — | 35 | 32 | 9 | 8 | 4 | 3 | 3 | 6 | 4 | 4 | 4 | 8 | 3 | 4 | 4 | 7 | 6 | 2 |
Swell 3 Height (m) Direction Period (s) | — | — | — | SE 14 | SE 13 | SSE 10 | SE 10 | SE 13 | SE 12 | SE 12 | S 15 | S 14 | E 7 | SE 6 | S 13 | SE 9 | SE 8 | SE 9 | E 10 | E 10 | — |
| kJ | — | — | — | 7 | 7 | 9 | 4 | 6 | 6 | 6 | 4 | 4 | 1 | 2 | 3 | 3 | 3 | 3 | 2 | 2 | — |
Wind waves Height (m) Direction Period (s) | — | S 4 | SSW 4 | — | SSW 4 | SW 4 | — | — | — | — | S 3 | — | — | S 3 | SSW 3 | S 3 | S 4 | S 3 | SSW 3 | S 3 | — |
| kJ | — | 18 | 20 | — | 10 | 18 | — | — | — | — | 1 | — | — | 4 | 3 | 1 | 12 | 6 | 1 | 3 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 77 | 77 | 14 | 14 | 76 | 10 | 0 | 0 | 16 | 16 | 18 | 38 | 18 | 76 | 76 | 18 | 77 | 76 | 77 | 491 | 92 |
Best forecast wave conditions in Kanagawa | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
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Information about the Rock Island Surf forecast
The above surf forecast table for Rock Island provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Rock Island can be found by selecting the local surf guide option on the grey menu. Our Rock Island surf forecast is unique since it includes wave energy (power) that defines the real feel of the surf rather than just the height or the period. If you surf the same spot (Rock Island) regularly then make a mental note of the wave energy from the surf forecast table each time you go. Very soon you may start to choose your surf days based on the wave energy alone combined with our forecast of favourable offshore wind conditions. Our star ratings will help here and of course you will also find the usual wave height and period predictions on our surf forecasts as well as a full break down of the swell components under our advanced users option (to reveal that, click the little Einstein character under the tide times).
Further information to help with frequently asked questions about our surf forecast for Rock Island may be found under the help tab on the top menu and also by moving your mouse over the question marks on the surf forecast table itself. Please always bear in mind that the forecast is for near-shore open water and local factors at each surf break influence the actual breaking wave height, such as the beach / reef profile, water depths offshore and shelter.
Rock Island is 3 km (2 miles) from the city of Kamakura. If you plan a holiday in Kanagawa, look for hotels and other accommodation in Kamakura. Kamakura has rooms for a wide range of budgets as well as car hire and transport links.
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