
Surf Forecasts:
Rock Island surf forecast from 5 Jul 2026:
- Best quality surf: Friday 10 Jul, 3AM (local time) - 6.5ft (2.0m), 16s period, S swell with glassy winds.
- Most powerful swell: Saturday 11 Jul, 3AM (local time) - 7.5ft (2.3m), 18s period, SSW swell with 3,237 kJ wave energy.
- Next surfable swell (1★+): Monday 6 Jul, 12AM (local time) - 3ft (0.9m), 7s period with SSE 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 06) at 12AM. The primary swell is predicted to be 0.9m and 7s period with a secondary swell of 0.1m and 15s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Rock Island in the next 16 days are 2.3m 18s and forecast to arrive on Saturday (Jul 11) at 3AM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 4s period and expected on Tuesday (Jul 07) at 12AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Mon 6th Jul) | 3ft (0.9m) 7s |
| Best Surf | 3AM (Fri 10th Jul) | 6.5ft (2.0m) 16s |
| Most Powerful | 3AM (Sat 11th Jul) | 7.5ft (2.3m) 18s |
Table - best surf conditions forecast for Rock Island over the next 16 days.
Updates in hr min s Forecast update imminent
Alright, Rusty here. Let’s talk about what’s cookin’ at Rock Island.
First things first – the water temp’s sittin’ around 74°, which is pretty much average for this time of year. Nothin' wild there.
We’ve got a bit of a slow start. Sunday the 5th is a total write-off with tiny, weak swell and choppy onshore junk. You’re better off waxin’ your board or stayin’ in bed. Monday the 6th shows a little glimmer of hope with a morning sesh – 4ft of SE swell, cross-off wind, and clean surf. The energy’s moderate (256), and it’s just enough to get a few fun ones. Nothin’ to write home about, but it’s surfable.
Now, Tuesday the 7th is where it starts to get interestin’. The morning is marginal with offshore wind but only 2ft, so it’s small and clean. But the afternoon? That’s the first real standout. Clean, offshore winds with a 3ft SSE swell and a very healthy 14-second period. The combined energy jumps to 613 (moderate), and that longer period means proper groundswell lines. The south swell direction is right on Rock Island’s optimum from the S, so expect nice, well-shaped waves. Crowds can pop up here sometimes, so keep your eyes peeled.
Wednesday the 8th morning is the absolute pick of the bunch for this whole run. We’re talkin’ 6ft of SSE swell with a 17-second period – that’s a very long-period groundswell. Combined energy is a hefty 1843, strong and powerful. Clean conditions with cross-off breeze. This is excellent, expert-level surf – over 5ft, so beginners might find it a handful. The long period means it’ll break a bit straight on the beach, but Rock Island is a reef setup, so it should handle that beautifully. If you’ve got the skills, this is your session. The afternoon turns onshore and messy, so get out early.
Thursday the 9th morning is glassy – perfect conditions – with 5ft of S swell at 15 seconds. Energy is still strong (1349). Another excellent session for experienced surfers. Clean, lined-up, and glassy. That’s a rare combo.
From Friday the 10th onward, the swell kicks up but the wind turns onshore. 7ft on Friday morning, 7ft on Saturday – these are big, powerful swells (energy over 2300). But the wind’s all wrong, blowin’ straight onshore, killin’ the shape. This is more of a kite-surfing setup than paddle-surfing. Unless you’re a seasoned charger lookin’ for a beatdown, steer clear.
By Sunday the 12th, the swell drops back under 5ft, but the wind stays messy. The rest of the second week is a slow fade – Monday the 13th has a small clean window in the morning with 3ft and offshore wind, but after that it’s mostly tiny, weak, and onshore. From around the 14th right through to the 20th, it’s a long stretch of poor conditions. The combined energy dips below 200 most days, and swell sizes hover below 2ft. Not worth gettin’ wet for.
So to sum it up: Wednesday morning the 8th is your absolute standout – big, clean, powerful, and well-shaped. Thursday morning the 9th is a close second with glassy perfection. After that, it’s a slow fade into flatness. Get it while it’s good.
Rusty.
Short Range ForecastHeavy rain (total 41mm), heaviest during Mon afternoon. Warm (max 25°C on Tue afternoon, min 20°C on Mon night). Winds increasing (light winds from the ESE on Sun morning, fresh winds from the NE by Mon night). | Days 4-6 Weather SummaryMostly dry. Warm (max 25°C on Wed afternoon, min 21°C on Wed night). Wind will be generally light. | ||||||||||||||||||||
Sunday 5 | Monday 6 | Tuesday 7 | Wednesday 8 | Thursday 9 | Friday 10 | Saturday 11 | |||||||||||||||
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) | SE 5 | SSE 6 | SSE 7 | SE 7 | SE 14 | SSE 14 | SSE 15 | SSE 14 | SE 16 | SSE 17 | SSE 16 | SSE 16 | S 15 | S 16 | S 16 | S 17 | SSW 16 | SSW 18 | SSW 17 | SSW 16 | SSW 16 |
Wave Graph | |||||||||||||||||||||
25 | 47 | 77 | 151 | 70 | 138 | 201 | 437 | 702 | 1714 | 1631 | 1324 | 991 | 1551 | 1750 | 2318 | 2458 | 3201 | 2876 | 1896 | 1474 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | cross-off | cross-off | cross-off | off | off | off | off | cross-off | on | cross | glassy | on | on | on | on | on | on | on | on |
High Tide | 9:18PM1.38m | 8:36AM1.27m | 9:50PM1.36m | 9:44AM1.18m | 10:23PM1.35m | 11:09AM1.11m | 11:00PM1.35m | 12:55PM1.10m | 11:41PM1.36m | 2:42PM1.15m | 00:30AM1.37m | 4:01PM1.24m | 1:22AM1.40m | ||||||||
Low Tide | 2:27PM0.29m | 3:05AM0.76m | 3:07PM0.44m | 4:01AM0.69m | 3:48PM0.60m | 5:04AM0.60m | 4:34PM0.76m | 6:12AM0.50m | 5:31PM0.91m | 7:19AM0.39m | 6:45PM1.02m | 8:19AM0.28m | 8:06PM1.09m | ||||||||
4:31 | — | — | 4:31 | — | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:35 | — | — | |
— | 7:00 | — | — | 7:00 | — | — | 6:59 | — | — | 6:59 | — | — | 6:59 | — | — | 6:59 | — | — | 6:58 | — | |
mm | 1 | — | 1 | 8 | 19 | 12 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 |
Temp °C | 24 | 24 | 23 | 21 | 21 | 20 | 23 | 25 | 22 | 24 | 25 | 23 | 24 | 24 | 23 | 24 | 25 | 24 | 25 | 25 | 24 |
Feels °C | 26 | 25 | 24 | 22 | 20 | 18 | 21 | 24 | 22 | 24 | 25 | 24 | 25 | 24 | 25 | 24 | 25 | 24 | 25 | 24 | 25 |
Swell 1 Height (m) Direction Period (s) | SSE 4 | SSE 6 | SSE 7 | SE 7 | SE 7 | SSE 14 | SSE 15 | SSE 14 | SE 16 | SSE 17 | SSE 16 | SSE 16 | S 15 | S 16 | S 16 | S 17 | SSW 16 | SSW 18 | SSW 17 | SSW 16 | SSW 16 |
4 | 47 | 77 | 49 | 47 | 138 | 201 | 437 | 702 | 1714 | 1631 | 1324 | 991 | 1551 | 1750 | 2318 | 2458 | 3201 | 2876 | 1896 | 1474 | |
Swell 2 Height (m) Direction Period (s) | SE 10 | SE 10 | SE 15 | SE 15 | SE 14 | SE 7 | SE 12 | ESE 8 | SSE 19 | E 9 | ESE 9 | S 20 | S 19 | ESE 8 | ESE 9 | ESE 8 | — | — | — | — | — |
4 | 4 | 9 | 54 | 70 | 29 | 67 | 64 | 375 | 129 | 103 | 125 | 358 | 33 | 44 | 20 | — | — | — | — | — | |
Swell 3 Height (m) Direction Period (s) | SW 6 | SE 16 | SSW 7 | SW 6 | SSE 16 | S 7 | SE 7 | SE 11 | SSE 19 | — | ESE 9 | — | — | — | — | — | — | — | — | — | — |
1 | 10 | 4 | 2 | 27 | 1 | 13 | 112 | 630 | — | 80 | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | SE 5 | — | — | SE 7 | — | NNE 4 | NNE 4 | NNE 3 | — | — | — | — | — | — | — | — | — | — | — | S 4 | SSW 4 |
25 | — | — | 151 | — | 14 | 7 | 7 | — | — | — | — | — | — | — | — | — | — | — | 12 | 15 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 228 | 54 | 0 | 0 | 145 | 0 | 145 | 0 | 0 | 0 | 18 | 12 | 0 | 18 | 14 | 18 | 64 | 14 | 76 | 77 | 12 |
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.










