Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 09 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
23.1° 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 8 Jul 2026:

  • Best quality surf: Thursday 9 Jul, 9AM (local time) - 6ft (1.9m), 14s period, SSE swell with glassy winds.
  • Most powerful swell: Saturday 11 Jul, 9AM (local time) - 7ft (2.2m), 17s period, S swell with 2,900 kJ wave energy.
  • Next surfable swell (1★+): Thursday 9 Jul, 9AM (local time) - 6ft (1.9m), 14s 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 Thursday (Jul 09) at 9AM. The primary swell is predicted to be 1.9m and 14s period with a secondary swell of 0.9m and 8s. 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 17s and forecast to arrive on Saturday (Jul 11) at 9AM. Winds are predicted to be onshore at the time the swell arrives.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9AM (Thu 9th Jul)6ft (1.9m) 14s
Best Surf 9AM (Thu 9th Jul)6ft (1.9m) 14s
Most Powerful 9AM (Sat 11th Jul)7ft (2.2m) 17s

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


Alright, Rusty here. Let’s cut through the noise and talk about what’s coming for Onjuku.

Honestly, the next couple of weeks are a bit of a mixed bag. We’ve got some serious size rolling in, but the wind is going to be our worst enemy for most of it. The real highlight is going to be Thursday morning, July 9. That’s the one to point the car at.

Thursday morning, July 9 is the standout. Onjuku is looking at a solid 6 ft swell from the SSE, with a nice 14-second period – that’s proper groundswell energy. The water is running 74°, which is a touch colder than normal for this time of year, so you’ll want a decent suit. But the real magic is the wind: glassy. Dead calm. Just a slight air. It’s going to be clean as a whistle. The combined energy is strong at 1626, so there’s plenty of push. This is excellent, powerful surf for experienced surfers. The shape should be good, and with that kind of period, expect long, lined-up sets. It’s an exposed break (Chiba), and the swell direction is right on the money from the SSE. You’ll want to be on it early.

Later Thursday afternoon, the wind shifts to a light cross-onshore from the SSE, so it will get a little bumpy. Friday through Sunday, the swell actually builds, getting up to 7 ft from the S and periods hitting 17 seconds on Saturday morning – that’s very long period stuff. The combined energy is massive, jumping to 2964. But it’s all onshore wind. Onshore from the S and SSW, blowing 9 to 12 mph. That’s onshore, messy, and blown-out. For the experienced crew, Saturday morning with that long-period S swell might offer some heavy, raw power, but it’s going to be a battle against the wind chop. It’s really only for the experts wanting a challenge. For most of us, it’s a skip.

Sunday stays similar, with onshore winds and dropping size. Monday the 13th is a write-off in the morning with light rain and strong cross-onshore wind, but Monday afternoon shows a glimmer: a 4 ft S swell, light cross-offshore wind from the WNW, and it’s clean. The energy is weak at 480, but it could offer a few fun, clean waves if you’re desperate.

From Tuesday the 14th onward, we hit a proper lull. Swell drops to tiny – 2 ft to 3 ft – and the combined energy falls below 200. The wind is messy or onshore. This flat spell looks set to last through the end of the second week, with barely anything rideable until around Monday, July 20, when a new 4 ft SSE pulse shows up, but it’s still onshore and unappealing.

Then, from Tuesday, July 21, a new, much bigger SSW/S swell starts to build. Tuesday afternoon sees 10 ft from the SSE with a strong 3414 combined energy. By Wednesday the 22nd, we’re looking at 12 ft from the S with energy over 5000. That’s a serious, powerful groundswell with a 14-second period – huge, powerful, and dangerous. The problem is it’s still forecast to be onshore. That much size with onshore wind creates a brutal, messy, closed-out beast. Only for kamikaze experts, and even then… It could be more interesting for kitesurfing than paddle surfing. Thursday the 23rd and Friday the 24th see the swell drop back to the 6 ft to 8 ft range, still onshore.

So, the takeaway? Thursday morning July 9 is your one truly good window of clean, powerful surf. The rest is either blown out, too small, or too big and messy. Keep an eye on that long-range stuff on the 21st and 22nd, but don’t hold your breath for it to be clean.

Rusty.

Short Range Forecast

Mostly dry. Warm (max 25°C on Thu morning, min 23°C on Thu night). Wind will be generally light.

Days 4-6 Weather Summary

Heavy rain (total 23mm), heaviest during Sun night. Warm (max 27°C on Tue morning, min 23°C on Sun night). Wind will be generally light.

Thursday
9
Friday
10
Saturday
11
Sunday
12
Monday
13
Tuesday
14
Wednesday
15
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
4
2
2
2
1
2
1
0
1
2
1
0
0
2
2
1
1
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)
1.9
SSE
14
1.6
SSE
13
2
S
14
2.1
S
15
2.2
S
16
2.2
S
16
2.2
S
17
2.2
S
17
2.1
SSW
16
1.9
SSW
16
1.6
SSW
16
1.3
SSW
15
1
SSW
14
1.1
S
12
0.8
SSW
12
0.7
SSW
11
0.7
SSW
11
0.7
SE
9
0.8
ESE
9
0.8
ESE
9
0.8
ESE
9
Wave Graph
Metric surfscale
Energy kJ
1306
828
1663
1847
2369
2542
2900
2702
2269
1899
1278
786
419
383
189
130
121
90
110
106
101
Wind (km/h)
5
SE
10
SSE
10
SSW
15
S
20
S
15
SSW
15
S
20
SSW
20
SSW
15
SW
15
SW
20
SSW
20
SSW
10
WNW
0
WSW
5
E
10
SSE
10
SSW
10
SSW
20
S
15
SSW
Wind State
glassy
cross-on
on
on
on
on
on
on
on
cross-on
cross-on
on
cross-on
cross-off
glassy
glassy
on
cross-on
on
on
on
High Tide
12:13PM1.01m
10:46PM1.33m
2:21PM1.09m
11:39PM1.34m
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
Low Tide
4:20PM0.89m
6:39AM0.36m
5:47PM1.02m
7:44AM0.22m
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
part cloud
clear
clear
clear
clear
clear
part cloud
cloud
cloud
cloud
light rain
thunderstorm
mod rain
rain showers
part cloud
part cloud
part cloud
part cloud
part cloud
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:31
4:31
4:31
4:33
4:33
4:33
4:33
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:54
6:54
6:54
6:53
6:53
6:53
6:52
 mm
1
13
8
1
Temp °C
25
25
24
25
25
24
25
25
24
25
24
24
24
24
24
27
26
25
27
27
25
Feels °C
27
26
26
27
26
26
26
25
25
27
26
26
25
27
28
30
29
29
29
29
27
  • 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