Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 21 Sep 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
23.9°C
1.6° 

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


Onjuku surf forecast from 21 Sep 2026:

  • Best quality surf: Monday 21 Sep, 6PM (local time) - 21ft (6.5m), 13s period, SSE swell with cross-shore winds.
  • Most powerful swell: Tuesday 22 Sep, 12AM (local time) - 21ft (6.5m), 14s period, SSE swell with 14,469 kJ wave energy.
  • Next surfable swell (1★+): Monday 21 Sep, 6PM (local time) - 21ft (6.5m), 13s period with SSE 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 Monday (Sep 21) at 6PM. The primary swell is predicted to be 6.5m and 13s period with a secondary swell of 4.0m and 11s. Another secondary swell of 3.0m and 13s is also forecast. The wind is predicted to be cross-shore as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 6.5m 14s and forecast to arrive on Tuesday (Sep 22) at 12AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.9m 5s period and expected on Tuesday (Sep 22) at 12AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 6PM (Mon 21st Sep)21ft (6.5m) 13s
Best Surf 6PM (Mon 21st Sep)21ft (6.5m) 13s
Most Powerful12AM (Tue 22nd Sep)21ft (6.5m) 14s

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


Short Range Forecast

Heavy rain (total 79mm), heaviest during Mon night. Warm (max 27°C on Mon morning, min 21°C on Wed night). Mainly near gales.

Days 4-6 Weather Summary

Some drizzle, heaviest during Thu morning. Warm (max 24°C on Fri morning, min 20°C on Sat night). Wind will be generally light.

Monday
21
Tuesday
22
Wednesday
23
Thursday
24
Friday
25
Saturday
26
Sunday
27
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
0
0
!
3
2
1
1
0
2
0
0
0
0
0
1
0
0
1
1
1
0
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
5
S
13
4
SE
12
6.5
SSE
14
1.7
SSE
10
1.6
SSE
9
1.2
ENE
9
1.3
ENE
9
0.8
ENE
8
1.1
ENE
9
1
ENE
9
0.7
ENE
9
0.6
ENE
8
0.3
ESE
8
1.4
ENE
7
0.8
ENE
6
1
E
8
0.2
SSE
10
1.5
E
7
1.3
E
7
1.1
E
7
0.9
E
6
Wave Graph
Metric surfscale
Energy kJ
8223
4493
14469
539
374
217
273
82
176
147
79
55
14
171
56
127
9
217
162
107
63
Wind (km/h)
35
SE
40
ESE
55
N
0
ENE
20
ENE
20
NE
25
ENE
20
ENE
10
ENE
20
NNE
20
NE
20
NE
20
ENE
20
ENE
15
NE
25
NNE
30
NE
20
NNE
15
NNE
10
NE
15
S
Wind State
cross-on
cross-on
off
glassy
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
off
cross-off
on
High Tide
3:28PM1.16m
11:46PM1.11m
3:22PM1.21m
1:26AM1.17m
3:32PM1.27m
2:24AM1.25m
3:45PM1.32m
3:10AM1.33m
4:01PM1.37m
3:52AM1.40m
4:19PM1.41m
4:33AM1.43m
4:37PM1.44m
Low Tide
8:11PM1.06m
7:49AM0.43m
8:35PM0.94m
8:31AM0.37m
9:01PM0.82m
9:06AM0.34m
9:27PM0.68m
9:37AM0.33m
9:55PM0.54m
10:07AM0.37m
10:24PM0.40m
10:36AM0.43m
10:55PM0.28m
mod rain
thunderstorm
heavy rain
cloud
part cloud
light rain
part cloud
part cloud
rain showers
light rain
cloud
part cloud
part cloud
clear
part cloud
cloud
cloud
cloud
cloud
cloud
cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
5:24
5:24
5:26
5:26
5:26
5:28
5:28
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
5:37
5:36
5:35
5:34
5:31
5:30
5:29
 mm
10
14
53
1
1
1
Temp °C
27
27
26
26
24
23
23
23
23
22
23
23
24
23
23
22
22
21
22
22
24
Feels °C
27
24
22
30
25
23
21
21
23
22
24
24
22
21
23
20
18
20
23
23
22
  • 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 
submit an eyeball surf report

Quick surf report for Onjuku:

join our community of surf reporters

FREE! Surf-Forecast.com widget for your website

The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Onjuku surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.


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.

Nearest locationNearest