Rock Island Surf Break

Lat Long: 35.29° N 139.55° E

Rock Island 48 hour detailed Surf Forecast

Issued: 8 am 21 Jul 2026 (local time)

Forecast update in  hr  min

Today's Rock Island sea temperature is
26.2° C
0.5° 

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


How big are the waves at Rock Island today (21 Jul):

  • Morning surf: Morning surf (21 Jul, local time) - 0.5ft (0.2m), 8s period with SSE swell.
  • Afternoon surf: Afternoon surf (21 Jul, local time) - 2ft (0.6m), 4s period with SSW swell.
  • Evening surf: Evening surf (21 Jul, local time) - 2.5ft (0.7m), 4s period with SSW swell.

The current surf forecast for Rock Island at 12PM is: 0.2m 11s primary swell from a East-southeast direction and 0.2m 8s secondary swell from a South-southeast direction, 0.1m 11s secondary swell from a East direction, 0.4m 3s secondary swell from a South-southwest direction (forecast issued at 08:00am July 21). The wind direction is predicted to be onshore.

Time (JST) & DateWave HeightWave Period
Morning (21 Jul)0.5ft (0.2m)8s
Afternoon (21 Jul)2ft (0.6m)4s
Evening (21 Jul)2.5ft (0.7m)4s

Table - waves today at Rock Island. (Swell directed towards the surf break)


Short Range Forecast

Moderate rain (total 10mm), heaviest on Thu night. Warm (max 32°C on Thu morning, min 27°C on Thu night). Wind will be generally light.

Tuesday
21
Wednesday
22
Thursday
23
6 AM
9 AM
12 PM
3 PM
6 PM
9 PM
12 AM
3 AM
6 AM
9 AM
12 PM
3 PM
6 PM
9 PM
12 AM
3 AM
6 AM
9 AM
12 PM
3 PM
6 PM
9 PM
Rating
(10 max)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.2
SSE
8
0.2
SSE
8
0.2
ESE
11
0.6
SSW
4
0.7
SSW
4
0.7
SSW
4
0.6
SSW
4
0.8
SW
4
0.6
SW
4
0.5
SW
4
0.4
SSW
4
0.5
S
3
0.5
SSW
4
0.6
SSW
4
0.5
SSW
4
0.7
SW
6
0.4
SSW
6
0.4
SSW
6
0.4
SSW
6
0.4
SSW
6
0.2
SSE
10
0.2
SSE
10
Wave Graph
Metric surfscale
Energy kJ
6
6
12
12
18
20
15
21
14
9
6
5
8
13
11
33
15
15
12
12
10
10
Wind (km/h)
10
SSW
10
SSW
20
S
25
SSW
20
SSW
20
SSW
10
SSW
5
NW
5
WNW
5
S
15
S
20
S
15
S
15
SSW
10
SSW
0
WSW
10
NE
15
NE
10
ENE
10
S
15
SSE
5
SE
Wind State
on
on
on
on
on
on
on
glassy
cross
cross-on
on
on
on
on
on
glassy
cross-off
cross-off
cross-off
cross-on
cross-on
cross-on
High Tide
9:03AM1.27m
9:33PM1.40m
10:14AM1.18m
10:05PM1.39m
11:48AM1.12m
Low Tide
3:12AM0.65m
3:07PM0.59m
4:07AM0.58m
3:45PM0.75m
5:11AM0.52m
4:29PM0.91m
clear
clear
clear
part cloud
clear
clear
thunderstorm
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
clear
thunderstorm
thunderstorm
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:41
4:41
4:43
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:53
6:52
6:52
 mm
1
1
4
Temp °C
27
29
29
29
29
28
28
28
28
29
29
28
28
29
28
28
28
29
32
31
30
28
Feels °C
31
33
31
31
31
31
33
33
33
34
32
31
31
33
32
34
32
32
35
34
34
33
  • Map Icons:
  • Break
  • Live Wave Height (m)
  • Live Wind Speed (km/h)
  • Surf Rating (10 Max)
  • Ocean Swells (m)
  • Wind Speed (km/h)
Map placeholder
How to use the Wavefinder 

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