Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 11 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
24.0° C
0.7° 

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


Onjuku surf forecast from 10 Jul 2026:

  • Best quality surf: Monday 13 Jul, 6AM (local time) - 4ft (1.2m), 13s period, SSW swell with glassy winds.
  • Most powerful swell: Saturday 11 Jul, 12PM (local time) - 7ft (2.2m), 16s period, S swell with 2,637 kJ wave energy.
  • Next surfable swell (1★+): Monday 13 Jul, 6AM (local time) - 4ft (1.2m), 13s period with SSW 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 (Jul 13) at 6AM. The primary swell is predicted to be 1.2m and 13s period with a secondary swell of 0.4m and 9s. The wind is predicted to be glassy as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 2.2m 16s and forecast to arrive on Saturday (Jul 11) at 12PM. Winds are predicted to be onshore at the time the swell arrives.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 6AM (Mon 13th Jul)4ft (1.2m) 13s
Best Surf 6AM (Mon 13th Jul)4ft (1.2m) 13s
Most Powerful12PM (Sat 11th Jul)7ft (2.2m) 16s

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


Alright, Rusty here. Let’s talk about what’s coming up for the next couple of weeks.

First off, we’ve got a bit of a flat spell to sit through. The immediate weekend is a write-off – Saturday and Sunday are looking pretty ordinary with messy cross-onshore winds and a large, long-period groundswell that’s just going to be lumpy and hard to manage. The combined energy is big, around 2691, but with the wind tearing it up, it’s not worth paddling out for. Wait it out.

The first real window of opportunity hits Monday morning, July 13th. Onjuku wakes up to a clean 3ft swell from the SSW, with a light offshore breeze from the north. The water is sitting at about 75°, which is just a touch cooler than average for this time of year, but nothing to worry about. That morning session will be the pick of the week – small but fun, with the wind dropping off to glassy by the afternoon. The swell period is a solid 13 seconds, so there’s some decent shape to the waves, but it’s inconsistent, so be patient.

After that, things taper off quickly. Through Tuesday and into the following week, the swell drops below 3ft and the wind turns onshore or cross-onshore again. The combined energy dips into the low hundreds, just weak background slop. It’s a long dry spell from Tuesday afternoon right through to the middle of the following week.

The next interesting pulse shows up on Tuesday, July 21st. The morning has a clean 4ft swell from the east with a cross-offshore breeze, but the combined energy is only moderate (293). It’s a marginal call, but the afternoon gets more interesting when a long-period 18-second groundswell from the SE rolls in, pushing the energy up to 675. This is a promising but less certain long-range signal – the swell direction is a good match for the spot, and the wind is clean. It’s not huge, but it could set up some nice lines.

The standout stretch, though, is looking like Wednesday, July 22nd, through Thursday, July 23rd. On Wednesday morning, we’ve got a solid 7ft swell from the ESE with a 12-second period, and a strong cross-offshore breeze from the NNE. The combined energy is pumping at 1570 – that’s serious wave energy. This is expert territory at that size, and the long period means it’ll be powerful and potentially walled-up at the beach, so take care. Thursday morning is even better: a 7ft swell from the ESE, a clean 30 km/h offshore wind from the north, and the energy at 1503. The conditions are fresh offshore and clean. This is the best on offer – a true standout for the big-wave crew. The consistency is fair, but the quality will be there.

After that, the swell fades again through the end of the week and into the weekend, with dropping size and strong winds keeping things messy. There’s a little spike on Sunday, July 26th, with a 6ft short-period swell from the ENE, but it’s a short-lived, choppy option with only moderate energy (433). Not worth a special trip.

So, if you’re looking for a wave, lock in Monday morning, July 13th, for clean small waves, and circle Wednesday the 22nd and Thursday the 23rd for the big, clean, powerful stuff. Expect crowds at Onjuku, especially on the better days.

Rusty.

Short Range Forecast

Moderate rain (total 19mm), heaviest on Sun night. Warm (max 27°C on Mon afternoon, min 23°C on Mon night). Wind will be generally light.

Days 4-6 Weather Summary

Some drizzle, heaviest during Thu night. Warm (max 27°C on Thu morning, min 24°C on Tue night). Wind will be generally light.

Saturday
11
Sunday
12
Monday
13
Tuesday
14
Wednesday
15
Thursday
16
Friday
17
AM
PM
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
2
2
2
1
0
1
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)
2.2
S
16
2.1
S
16
2.2
SSW
16
1.9
SSW
16
1.6
SSW
16
1.4
SSW
14
1
SSW
13
0.9
SSW
12
0.8
SSW
11
0.7
SSW
11
0.6
SSW
10
0.6
S
10
0.6
S
10
0.8
ESE
9
0.9
ESE
9
1
ESE
9
0.9
ESE
9
0.9
ESE
9
0.9
ESE
8
0.8
ESE
8
0.8
SSE
7
Wave Graph
Metric surfscale
Energy kJ
2632
2410
2339
1752
1278
789
356
254
167
123
85
73
70
84
111
144
116
135
103
92
69
Wind (km/h)
20
SSW
25
SSW
25
SSW
20
SW
25
SW
20
SW
10
N
5
N
10
NNW
5
ENE
10
SE
5
S
10
SSE
15
SSE
10
S
15
SSE
15
S
15
S
25
SSW
25
SSW
25
SSW
Wind State
cross-on
on
cross-on
cross-on
cross-on
cross-on
off
glassy
off
cross-off
cross-on
glassy
cross-on
on
on
on
on
on
on
on
cross-on
High Tide
3:42PM1.20m
00:41AM1.37m
4:34PM1.30m
1:44AM1.42m
5:16PM1.35m
2:44AM1.47m
5:52PM1.37m
3:40AM1.51m
6:24PM1.37m
4:33AM1.52m
6:54PM1.36m
5:24AM1.49m
7:20PM1.34m
Low Tide
7:27PM1.09m
8:43AM0.08m
8:45PM1.11m
9:36AM-0.02m
9:42PM1.09m
10:24AM-0.09m
10:29PM1.03m
11:09AM-0.09m
11:12PM0.96m
11:51AM-0.03m
11:55PM0.87m
12:29PM0.08m
00:40AM0.77m
part cloud
cloud
part cloud
cloud
thunderstorm
mod rain
light rain
part cloud
rain showers
part cloud
part cloud
clear
part cloud
part cloud
clear
clear
clear
rain showers
clear
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:31
4:33
4:33
4:33
4:33
4:35
4:35
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:54
6:53
6:53
6:53
6:52
6:52
6:52
 mm
4
9
1
5
1
Temp °C
25
25
25
25
25
25
26
27
25
26
26
24
26
26
25
27
27
27
28
28
26
Feels °C
26
25
26
25
26
28
30
30
29
30
29
28
29
28
27
29
29
29
29
29
28
  • Map Icons:
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  • 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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