Rock Island Surf Break

Lat Long: 35.29° N 139.55° E

Rock Island Surf Forecast and Surf Report

Issued: 8 pm 28 Aug 2026 (local time)

Forecast update in  hr  min

Today's Rock Island sea temperature is
28.0°C
1.2° 

Rock Island surf forecast is for near shore open water. Breaking waves will often be smaller at less exposed spots.


Rock Island surf forecast from 28 Aug 2026:

  • Most powerful swell: Thursday 3 Sep, 12PM (local time) - 3ft (0.9m), 11s period, S swell with 189 kJ wave energy.

Best Forecast Surf Conditions for Rock Island this week:

The most powerful waves expected at Rock Island in the next 16 days are 0.9m 11s and forecast to arrive on Thursday (Sep 03) at 12PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 3s period and expected on Saturday (Sep 05) at 3AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+)--
Best Surf--
Most Powerful12PM (Thu 3rd Sep)3ft (0.9m) 11s

Table - best surf conditions forecast for Rock Island over the next 16 days.


The Lowdown

Hey folks, Rusty here. Let’s get straight into what’s on the menu for Rock Island.

Alright, I’ll level with ya—this stretch isn’t looking like one for the memory books. We’ve got a whole heap of days where the swell is just too small and the wind is messing with things. The first real sniff of anything worth paddling out for doesn’t show up until Sunday morning, September 6th. That’s a solid week of flat or poor conditions to sit through before we get anything rideable.

So, come Sunday the 6th, early doors, we’ve got a little pulse of swell—2 ft from the SE at 8 seconds. That’s short-period, so it’ll be a bit weak and wonky, but the wind is glassy. Dead flat, no ripples—that’s a big positive. The combined energy is weak (82), so you’ll be hunting for the few that stand up. Rock Island is a reef setup, exposed to the south, and it’s fairly consistent, but this is a day for the small-wave kit. Water temp feels average for this time of year, nothing wild going on.

If you’re a beginner, that glassy window on Sunday the 6th morning is your best bet—it’s small, clean, and forgiving. The crowds can pop up here sometimes, so you might have a few for company.

After that, the swell tries to bump a little mid-week but the wind turns onshore and bloody strong. By Friday the 11th of September, we get a decent offshore wind from the NNE—25 km/h—and a clean surface, but the swell is only 2 ft from the SE with a long period of 13 seconds. That long period (over 11 seconds) means better shaped waves, but at a beach or reef it can break a bit straight. Energy is moderate (103). It’s surfable but nothing to call home about. Saturday the 12th goes backwards again with the same offshore wind but even smaller swell.

Honestly, the standout window is that glassy Sunday morning on the 6th, and maybe a small window on Friday the 11th if you’re desperate. It’s a lean couple of weeks—hang in there.

Rusty.

Short Range Forecast

Moderate rain (total 13mm), heaviest on Fri night. Warm (max 28°C on Fri night, min 21°C on Sat afternoon). Winds decreasing (fresh winds from the NNE on Sat afternoon, calm by Sun afternoon).

Days 5-7 Weather Summary

Light rain (total 3mm), mostly falling on Mon night. Warm (max 28°C on Tue afternoon, min 26°C on Mon night). Winds increasing (light winds from the SSW on Mon night, fresh winds from the SSW by Thu afternoon).

Saturday
29
Sunday
30
Monday
31
Tuesday
1
Wednesday
2
Thursday
3
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.6
SSW
7
0.4
SSW
7
0.2
SSE
11
0.3
SSW
8
0.3
SSW
8
0.2
SSE
10
0.2
SSE
10
0.2
SSE
10
0.2
SSE
10
0.3
SSW
10
0.4
SSW
10
0.4
SSW
10
0.5
SSW
9
0.5
S
9
0.6
S
10
0.8
S
10
0.7
SSW
11
0.6
SSW
11
0.8
SSW
10
Wave Graph
Metric surfscale
Energy kJ
40
18
12
11
11
10
10
9
9
19
38
35
48
43
65
125
128
93
123
Wind (km/h)
15
NNE
10
NE
30
NNE
25
NNE
15
NNE
5
NNE
5
NNE
5
NNE
10
SSW
10
S
5
S
20
S
15
S
15
S
25
S
30
SSW
30
SSW
30
SSW
30
SSW
Wind State
off
cross-off
off
off
off
off
off
off
on
on
on
on
on
on
cross-on
on
on
on
on
High Tide
5:19AM1.57m
6:18PM1.49m
6:04AM1.58m
6:41PM1.49m
6:48AM1.55m
7:03PM1.50m
7:33AM1.49m
7:26PM1.50m
8:22AM1.41m
7:51PM1.49m
9:19AM1.31m
8:17PM1.47m
Low Tide
11:30PM0.73m
11:54AM0.30m
00:05AM0.62m
12:27PM0.39m
00:39AM0.52m
12:58PM0.50m
1:16AM0.45m
1:29PM0.63m
1:56AM0.40m
1:58PM0.77m
2:40AM0.39m
2:27PM0.91m
mod rain
light rain
light rain
light rain
cloud
part cloud
cloud
part cloud
clear
thunderstorm
clear
clear
clear
clear
clear
rain showers
clear
clear
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
5:11
5:11
5:11
5:13
5:13
5:13
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:15
6:14
6:12
6:10
6:09
6:07
6:07
 mm
6
1
4
2
1
2
Temp °C
28
24
22
21
23
24
24
26
27
27
27
28
27
28
28
27
28
28
27
Feels °C
29
26
20
19
24
26
28
29
29
31
31
30
29
29
29
28
28
27
27
  • 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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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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