Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 8 pm 07 Sep 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
28.0°C
1.5° 

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


Onjuku surf forecast from 7 Sep 2026:

  • Best quality surf: Thursday 10 Sep, 9AM (local time) - 6ft (1.8m), 7s period, NE swell with offshore winds.
  • Most powerful swell: Tuesday 8 Sep, 3AM (local time) - 7ft (2.1m), 9s period, S swell with 742 kJ wave energy.
  • Next surfable swell (1★+): Thursday 10 Sep, 9AM (local time) - 6ft (1.8m), 7s period with NE swell.

Best Forecast Surf Conditions for Onjuku this week:

The surf forecast for Onjuku over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Sep 10) at 9AM. The primary swell is predicted to be 1.8m and 7s period with a secondary swell of 1.2m and 9s. Another secondary swell of 0.3m and 15s is also forecast. The wind is predicted to be offshore as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 2.1m 9s and forecast to arrive on Tuesday (Sep 08) at 3AM. Winds are predicted to be cross-shore at the time the swell arrives.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9AM (Thu 10th Sep)6ft (1.8m) 7s
Best Surf 9AM (Thu 10th Sep)6ft (1.8m) 7s
Most Powerful 3AM (Tue 8th Sep)7ft (2.1m) 9s

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


Short Range Forecast

Heavy rain (total 29mm), heaviest during Mon night. Warm (max 29°C on Wed morning, min 20°C on Wed night). Winds increasing (light winds from the W on Mon night, fresh winds from the SW by Wed morning).

Days 5-7 Weather Summary

Light rain (total 2mm), mostly falling on Thu night. Warm (max 26°C on Sun morning, min 19°C on Thu night). Winds decreasing (fresh winds from the NNE on Thu night, light winds from the NE by Fri night).

Tuesday
8
Wednesday
9
Thursday
10
Friday
11
Saturday
12
Sunday
13
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
3
1
0
0
0
0
1
3
2
2
2
2
1
2
1
1
1
2
2
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
3
S
9
1.7
S
9
1.5
S
9
1.6
S
9
2.1
S
8
2
S
8
1.8
NE
7
1.8
NE
7
1.7
NE
7
1.4
ENE
7
0.9
S
8
0.5
E
14
0.5
E
14
0.6
E
14
0.6
E
13
0.6
E
13
0.8
SE
9
0.9
SE
9
1
SE
9
Wave Graph
Metric surfscale
Energy kJ
1372
473
363
373
523
546
284
299
261
207
111
101
97
134
128
128
99
125
155
Wind (km/h)
10
WSW
10
SW
20
SSW
30
SSW
40
SW
30
SW
30
NE
20
NNE
30
NNE
25
N
15
NNE
15
NE
15
NNE
10
NE
10
ENE
10
NE
15
NE
15
ENE
5
SSE
Wind State
cross-on
cross-on
on
cross-on
cross-on
cross-on
cross-off
off
off
off
off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
glassy
High Tide
00:42AM1.25m
3:57PM1.30m
2:06AM1.33m
4:14PM1.34m
3:06AM1.40m
4:32PM1.36m
3:56AM1.45m
4:50PM1.39m
4:41AM1.47m
5:08PM1.41m
5:24AM1.44m
5:26PM1.43m
Low Tide
8:30AM0.20m
8:59PM0.95m
9:17AM0.17m
9:34PM0.80m
9:55AM0.18m
10:07PM0.64m
10:29AM0.24m
10:40PM0.50m
10:59AM0.34m
11:13PM0.38m
11:26AM0.45m
11:46PM0.30m
thunderstorm
part cloud
thunderstorm
thunderstorm
clear
rain showers
mod rain
light rain
cloud
light rain
cloud
cloud
cloud
cloud
part cloud
part cloud
part cloud
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
5:15
5:16
5:16
5:16
5:18
5:18
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
5:57
5:54
5:53
5:52
5:51
5:49
 mm
12
1
4
2
7
3
2
Temp °C
25
28
28
27
29
29
23
21
20
20
21
22
22
23
24
23
26
26
26
Feels °C
29
31
30
29
28
29
21
21
17
18
22
23
25
26
27
26
29
29
31
  • 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 Onjuku Surf forecast

The above surf forecast table for Onjuku provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Onjuku can be found by selecting the local surf guide option on the grey menu. Our Onjuku 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 (Onjuku) 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 Onjuku 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.

Onjuku is 3 km (2 miles) from Ohara. If you plan a holiday in Chiba, look for hotels and other accommodation in Ohara. Ohara has rooms for a wide range of budgets as well as car hire and transport links.

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