Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 21 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
25.3° C
0.2° 

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


Onjuku surf forecast from 20 Jul 2026:

  • Best quality surf: Monday 27 Jul, 3AM (local time) - 4ft (1.2m), 6s period, SW swell with glassy winds.
  • Most powerful swell: Tuesday 21 Jul, 9AM (local time) - 3.5ft (1.1m), 10s period, E swell with 252 kJ wave energy.
  • Next surfable swell (1★+): Thursday 23 Jul, 9AM (local time) - 2.5ft (0.8m), 10s period with E 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 (Jul 23) at 9AM. The primary swell is predicted to be 0.8m and 10s period with a secondary swell of 0.4m and 5s. Another secondary swell of 0.6m and 5s is also forecast. The wind is predicted to be glassy as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 1.1m 10s and forecast to arrive on Tuesday (Jul 21) at 9AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.9m 5s period and expected on Tuesday (Jul 28) at 9AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9AM (Thu 23rd Jul)2.5ft (0.8m) 10s
Best Surf 3AM (Mon 27th Jul)4ft (1.2m) 6s
Most Powerful 9AM (Tue 21st Jul)3.5ft (1.1m) 10s

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


The Lowdown

Alright folks, Rusty here. Let’s have a look at what’s cookin’ for Onjuku over the next couple of weeks.

Right off the bat, it’s a bit of a slow start. We’re looking at a stretch of pretty ordinary conditions from the get-go, lasting through the first week and a half. The surf is small and the wind is mostly cross-onshore, making for some choppy, poor surf. There’s a brief window of clean, glassy conditions on the morning of Thursday the 23rd, but the swell is only 3ft out of the east, so it’s very mediocre. You’ll find a few mornings with light winds and clean faces, like the 24th Friday morning (2ft east) and the 25th Saturday morning (1ft southeast), but the energy is weak, with combined swell energy readings of just 82 and 164 respectively. Nothing to get excited about.

The real story, the one that’s worth circling on the calendar, is the first week of August. The wait is long, but it’s gonna pay off.

The standout is the morning of Tuesday, August 4th. This is the goods. We’ve got a solid 5ft swell rolling in from the south, with a very long period of 15 seconds – that’s proper groundswell energy. The combined energy is a massive 1859, so there’s plenty of push. The wind is a clean, light cross-offshore from the northeast, which will keep the faces tidy. This is a setup built for experienced surfers, so if you’ve got the skill, this is your session. The long period will make the waves powerful and well-shaped, but at a beach break, it can be a bit straight, so keep your eyes on the peaks.

The morning of Wednesday, August 5th, is a close second. Another 5ft swell, this time from the east-southeast, with a long period of 14 seconds. The combined energy is 1117, still strong, and the wind is dead glassy from the east. That’s a recipe for some of the cleanest, most inviting waves you’ll see all forecast. The wave heights are in the zone for experts, but the glassy conditions make it very appealing.

Before that, the morning of Monday, August 3rd, shows a bit of promise with a 5ft south swell and 13 seconds of period, but the wind is cross-shore, so you’ll have some chop to deal with. The energy is building though, at 1273.

For the rest of the period, it’s a write-off. The wind stays strong and cross-onshore, spoiling any chance of clean surf, even when the swell tries to pick up. If you’re a kitesurfer, some of those windy afternoons at the end of July and start of August look a lot more interesting, with 5ft to 5ft swells and fresh cross-onshore winds.

So, to put it plain: hang tight. The first week is a write-off. The second week, specifically the mornings of the 4th and 5th of August, are your best bets. Mark them down, but remember, it’s a long-range call, so keep an eye on the forecast as it gets closer.

Rusty.

Short Range Forecast

Mostly dry. Warm (max 30°C on Tue morning, min 26°C on Tue night). Wind will be generally light.

Days 4-6 Weather Summary

Moderate rain (total 15mm), heaviest on Fri night. Warm (max 28°C on Fri morning, min 22°C on Sat night). Wind will be generally light.

Tuesday
21
Wednesday
22
Thursday
23
Friday
24
Saturday
25
Sunday
26
Monday
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
0
1
0
0
1
0
0
1
0
1
1
0
0
1
1
0
1
1
2
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
1.1
E
10
1.1
E
10
1
E
10
1
E
10
0.9
E
10
0.8
E
10
0.8
E
10
0.7
E
9
0.6
E
9
0.6
E
9
0.5
SE
11
0.4
SE
16
0.4
SE
16
0.4
SE
16
0.4
SE
15
0.5
SE
10
0.4
SE
15
0.5
SE
10
0.8
SSW
7
0.8
SSW
7
0.7
SSW
9
Wave Graph
Metric surfscale
Energy kJ
252
247
196
196
156
121
113
81
58
57
57
66
65
63
57
54
64
53
58
67
90
Wind (km/h)
15
SW
25
SW
15
SW
10
SW
25
SW
15
SW
0
SW
10
SSW
5
SW
0
NNE
10
SSW
10
N
10
NE
15
E
15
NE
15
NE
5
ENE
5
ESE
5
S
0
SE
10
NE
Wind State
cross-on
cross-on
cross-on
cross-on
cross-on
cross-on
glassy
on
cross-on
glassy
on
off
cross-off
cross
cross-off
cross-off
cross-off
cross
glassy
glassy
cross-off
High Tide
9:07AM1.04m
8:57PM1.32m
10:41AM0.95m
9:26PM1.31m
10:06PM1.28m
11:05PM1.26m
4:30PM1.13m
00:24AM1.25m
4:42PM1.19m
1:35AM1.28m
5:00PM1.23m
2:32AM1.33m
Low Tide
2:24PM0.72m
4:14AM0.54m
2:41PM0.85m
5:28AM0.50m
6:45AM0.44m
7:51AM0.37m
7:16PM1.10m
8:43AM0.30m
8:40PM1.07m
9:26AM0.23m
9:28PM1.02m
clear
clear
clear
clear
clear
clear
clear
clear
clear
part cloud
thunderstorm
thunderstorm
clear
clear
thunderstorm
light rain
part cloud
part cloud
part cloud
part cloud
part cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:37
4:39
4:39
4:39
4:41
4:41
4:43
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:50
6:50
6:49
6:47
6:47
6:46
6:45
 mm
2
7
2
4
Temp °C
30
30
26
30
30
27
29
29
27
28
28
26
28
27
24
23
24
25
28
27
25
Feels °C
32
32
29
33
33
30
35
33
31
34
33
29
31
30
26
25
27
29
33
32
29
  • 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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