Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 8 am 13 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
24.6° C
0.4° 

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


Onjuku surf forecast from 13 Jul 2026:

  • Best quality surf: Sunday 19 Jul, 6PM (local time) - 5ft (1.6m), 9s period, ESE swell with cross-offshore winds.
  • Most powerful swell: Monday 20 Jul, 12AM (local time) - 6ft (1.8m), 9s period, ESE swell with 499 kJ wave energy.
  • Next surfable swell (1★+): Monday 13 Jul, 9PM (local time) - 3.5ft (1.0m), 12s period with S 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 9PM. The primary swell is predicted to be 1.0m and 12s period with a secondary swell of 0.3m and 9s. The wind is predicted to be offshore as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 1.8m 9s and forecast to arrive on Monday (Jul 20) at 12AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 3s period and expected on Saturday (Jul 18) at 9AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9PM (Mon 13th Jul)3.5ft (1.0m) 12s
Best Surf 6PM (Sun 19th Jul)5ft (1.6m) 9s
Most Powerful12AM (Mon 20th Jul)6ft (1.8m) 9s

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


Alright folks, Rusty here. Let’s have a look at what Onjuku is cooking up for us.

First up, the water temperature is sitting at 76°, which is about normal for this time of year – nothing crazy there.

The forecast starts off with a bit of a slow burn. Monday the 13th has a morning window with a 4 ft SSW swell, period of 13 seconds, and a cross-offshore wind. The combined energy is moderate at 475, and it’s looking clean. That’s the best we’ve got in the early days, but it’s not a standout. The rest of the week is mostly a write-off with onshore winds, small surf, and messy conditions. There’s a real lull mid-week, with Wednesday the 15th through Friday the 17th offering almost nothing worth paddling out for.

Now, things start to get interesting heading into the weekend of the 18th and 19th. On Saturday the 18th, we’ve got a 4 ft to 4 ft ESE swell with clean conditions thanks to a cross-offshore NE wind. The energy bumps up to 310-332, but it’s still just a marginal call. Sunday the 19th afternoon looks a bit better with a 5 ft ESE swell, again clean, and the energy climbing to 444. It’s getting there, but not quite a standout.

The real highlight, and the one you want to circle, is Wednesday the 22nd. The morning session is where it’s at. We’re looking at a 7 ft E swell with a period of 11 seconds, zero wind – glassy as it gets. The combined energy is a solid 1228, which is strong. This is expert territory at that size, but the conditions are prime. The swell direction from the E is a touch off the optimum SSE, but for a clean, glassy morning with that much power, it’s the pick of the 16 days by a long shot. After that, the swell backs off and the wind turns messy again.

Overall, there’s a long gap of poor surf from the 13th through the 17th, then a slow build to that one standout morning on the 22nd. After that, it’s a mix of marginal and poor conditions through the rest of the window. The 22nd is the one to chase if you’ve got the skill.

Rusty.

Short Range Forecast

Some drizzle, heaviest during Mon morning. Warm (max 28°C on Tue morning, min 24°C on Mon night). Winds increasing (calm on Tue morning, fresh winds from the SSW by Wed night).

Days 4-6 Weather Summary

Moderate rain (total 10mm), heaviest on Thu night. Warm (max 27°C on Thu morning, min 24°C on Fri night). Wind will be generally light.

Monday
13
Tuesday
14
Wednesday
15
Thursday
16
Friday
17
Saturday
18
Sunday
19
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
2
0
2
1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
2
3
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
SSW
13
0.8
SSW
12
0.9
SSW
11
0.7
SSW
11
0.6
SSW
10
0.5
S
10
0.4
SSW
10
0.5
E
9
1.4
SSW
6
1.1
S
6
0.7
E
8
0.7
E
8
0.8
E
9
0.8
E
9
0.8
E
8
1.1
SE
10
1.3
ESE
9
1.2
E
8
1
SE
10
1.4
ESE
9
1.8
ESE
9
Wave Graph
Metric surfscale
Energy kJ
424
167
213
123
86
51
31
39
122
77
66
71
99
94
90
261
295
195
216
311
499
Wind (km/h)
5
NE
10
WSW
10
NNE
5
SSE
15
S
15
SSW
20
SSW
25
SSW
35
SSW
25
SSW
20
S
15
S
15
SSE
15
SE
10
NE
20
NE
25
NE
20
NNE
20
NNE
15
ENE
15
NE
Wind State
cross-off
cross-on
cross-off
glassy
on
cross-on
cross-on
on
cross-on
cross-on
on
on
on
cross-on
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
cross-off
High Tide
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
6:15AM1.41m
7:45PM1.33m
7:06AM1.30m
8:08PM1.33m
Low Tide
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
1:04PM0.23m
1:26AM0.69m
1:34PM0.40m
2:16AM0.63m
thunderstorm
cloud
part cloud
part cloud
part cloud
clear
clear
part cloud
part cloud
part cloud
part cloud
rain showers
thunderstorm
part cloud
part cloud
part cloud
part cloud
part cloud
cloud
light rain
cloud
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:33
4:33
4:33
4:35
4:35
4:35
4:37
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:53
6:53
6:52
6:52
6:52
6:52
6:51
 mm
1
8
2
1
Temp °C
26
27
26
28
28
26
28
27
26
27
27
26
27
27
25
26
26
24
25
26
25
Feels °C
30
31
29
31
30
28
30
28
26
29
29
29
30
29
28
26
27
25
27
29
28
  • 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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