Rock Island surfForecast / Kanagawa / Japan

information circle48hr Weather and Surf, issued 2 am Wednesday 13 May 2026 JST
Forecast 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
20.1° C
(Which is normal for this time of year)

How big are the waves at Rock Island today?

The current surf forecast for Rock Island at 8AM is: 0.6m 9s primary swell from a Southeast direction and 0.1m 9s secondary swell from a South direction (forecast issued at 02:00am May 13). The wind direction is predicted to be offshore.

Time (JST) & DateWave HeightWave Period
Morning (13 May)2ft (0.6m)9s
Afternoon (13 May)1.5ft (0.5m)9s
Evening (13 May)1.5ft (0.4m)9s

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


Updates in  hr  min  s Forecast update imminent

Short Range Forecast

Light rain (total 6mm), mostly falling on Wed night. Warm (max 21°C on Wed morning, min 15°C on Thu night). Wind will be generally light.

Wednesday
13
Thursday
14
Friday
15
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
12 AM
3 AM
6 AM
9 AM
12 PM
3 PM
6 PM
9 PM
Rating
(10 max)
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Swell
Height Map
Height MapHeight MapHeight Map
Height MapHeight MapHeight Map
Height MapHeight MapHeight Map
Wave
Height (m)
Direction
Period (s)
0.6
SE
9
0.6
SE
9
0.6
SE
9
0.6
SE
9
0.5
SE
9
0.5
SE
9
0.4
SE
9
0.4
SE
9
0.4
SE
10
0.4
SE
10
0.4
SE
10
0.3
ESE
10
0.2
ESE
10
0.2
ESE
10
0.2
ESE
10
0.4
SE
10
0.2
ESE
11
0.2
SSE
6
0.2
SSE
6
0.2
SSE
7
0.2
SSE
6
0.3
SE
8
0.3
SE
8
0.2
ESE
8
Wave Graph
Metric surfscale
Energy kJ
51
50
49
50
41
41
31
29
34
33
34
19
9
10
9
27
11
5
5
6
5
13
11
6
Wind (km/h)
0
SSE
5
NE
10
NNE
5
ENE
5
SW
20
S
15
SSW
10
SW
5
N
10
N
10
NE
15
NE
10
ENE
10
SE
10
S
20
E
20
NE
15
NE
20
NE
15
NE
5
E
20
S
15
SSW
10
S
glassy
glassy
off
cross-off
glassy
cross-on
on
on
glassy
off
off
cross-off
cross-off
cross-on
cross-on
cross-off
cross-off
cross-off
cross-off
cross-off
glassy
on
on
on
High Tide
2:10AM1.25m
2:50PM1.17m
2:40AM1.28m
3:50PM1.25m
3:10AM1.32m
4:42PM1.32m
Low Tide
8:37AM0.48m
8:38PM0.60m
9:17AM0.32m
9:25PM0.66m
9:56AM0.17m
clear
clear
clear
clear
clear
part cloud
cloud
thunderstorm
cloud
light rain
thunderstorm
thunderstorm
thunderstorm
rain showers
clear
part cloud
part cloud
clear
clear
clear
clear
clear
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:39
4:39
4:37
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:36
6:37
6:37
1
1
1
1
1
1
Temp °C
18
18
17
19
21
21
20
20
19
18
18
18
20
21
20
17
16
15
15
16
19
19
19
18
19
18
16
18
21
18
18
20
19
17
17
16
19
20
20
14
13
12
12
14
19
16
17
18
Swell 1
Height (m)
Direction
Period (s)
0.6
SE
9
0.6
SE
9
0.6
SE
9
0.6
SE
9
0.5
SE
9
0.5
SE
9
0.4
SE
9
0.4
SE
9
0.4
SE
10
0.4
SE
10
0.4
SE
10
0.3
ESE
10
0.2
SSE
8
0.2
SSE
7
0.2
SSE
7
0.4
SE
10
0.3
SE
6
0.2
SSE
6
0.2
SSE
6
0.2
SSE
7
0.2
SSE
6
0.3
SE
8
0.3
SE
8
0.2
ESE
8
Energy kJ
51
50
49
50
41
41
31
29
34
33
34
19
6
5
5
27
7
4
3
5
4
11
11
6
Swell 2
Height (m)
Direction
Period (s)
0.1
S
9
0.1
S
9
0.1
SE
11
0.2
ESE
11
0.1
SE
11
0.1
SE
10
0.1
SE
10
0.2
SSE
8
0.2
ESE
10
0.2
ESE
10
0.1
SE
11
0.1
E
9
0.2
ESE
11
0.1
SE
11
0.1
SE
9
0.1
SE
11
0.1
SE
10
0.1
SE
12
0.1
SE
11
0.1
SE
11
Energy kJ
2
1
5
12
5
4
4
6
9
10
4
2
11
5
3
5
4
5
5
5
Swell 3
Height (m)
Direction
Period (s)
0.1
SE
11
0.1
S
8
0.1
S
7
0.1
SE
10
0.1
SE
10
0.1
SE
10
0.2
ESE
10
0.1
S
7
0.1
SE
8
0.1
SE
8
0.1
SE
11
0.1
SE
12
0.1
SE
12
0.2
SSE
11
0.1
S
7
0.1
S
7
Energy kJ
4
1
1
4
4
4
9
1
3
3
5
6
5
13
1
1
Wind waves
Height (m)
Direction
Period (s)
0.3
S
3
0.3
SSE
3
0.2
SSE
3
Energy kJ
1
2
1
Nearest Offshore or Glassy
Rating
(10 max)
1
1
1
1
1
1
2
1
1
1
1
1
1
2
2
1
2
2
2
1
2
1
1
2
Distance (km)
0
0
0
0
16
64
51
16
16
16
38
38
38
16
38
38
51
38
51
16
16
64
64
51
Best forecast wave conditions in Kanagawa
Rating
(10 max)
1
1
1
1
1
1
1
1
1
2
2
1
2
Best forecast wave conditions in Japan
Rating
(10 max)
2
2
2
2
3
3
3
3
3
3
2
2
2
2
2
2
2
2
2
2
2
1
1
2
Header Global
Rating
(10 max)
8
9
9
9
9
9
9
8
7
9
9
9
9
8
5
5
5
5
5
5
5
5
5
5
  • 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

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