Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 15 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
25.1° C
0.0° 

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


Onjuku surf forecast from 14 Jul 2026:

  • Best quality surf: Monday 20 Jul, 9PM (local time) - 4.5ft (1.4m), 10s period, E swell with glassy winds.
  • Most powerful swell: Monday 20 Jul, 9PM (local time) - 4.5ft (1.4m), 10s period, E swell with 410 kJ wave energy.
  • Next surfable swell (1★+): Monday 20 Jul, 9PM (local time) - 4.5ft (1.4m), 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 Monday (Jul 20) at 9PM. The primary swell is predicted to be 1.4m and 10s period with a secondary swell of 0.4m and 8s. Another secondary swell of 0.3m and 8s 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 1.4m 10s and forecast to arrive on Monday (Jul 20) at 9PM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.9m 4s period and expected on Wednesday (Jul 22) at 9AM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9PM (Mon 20th Jul)4.5ft (1.4m) 10s
Best Surf 9PM (Mon 20th Jul)4.5ft (1.4m) 10s
Most Powerful 9PM (Mon 20th Jul)4.5ft (1.4m) 10s

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


The Lowdown

Alright, let’s get into it. This is Rusty, and I’m looking at the next few weeks for Onjuku. I gotta be straight with you—this is a bit of a slow burn. There’s a long dry spell at the start, so don’t get your hopes up for the first week. We’ve got a decent window of cleaner conditions later on, but you’ll need to be patient.

The first notable surf comes in on Monday, July 20th, but it’s marginal. The water temp is sitting at a comfortable 77°, which is pretty much spot on average for this time of year. The real action doesn’t start to shape up until the early morning of Monday, July 21st. That’s when we get a shift. The wind goes light offshore from the NE, and the swell turns on at 4 ft from the east with a nice 11-second period. That’s a proper groundswell, and the combined energy is solid (393). It’s going to be clean, but keep in mind that long period swell like this can make the waves a bit straight at beach breaks; Onjuku is an exposed spot, so with that east direction, it could work. The crowd factor is listed as “sometimes,” so you might have some company.

The best windows in this whole outlook are the mornings of Saturday, July 25th, and Sunday, July 26th. Saturday morning is a real standout. The wind goes dead glassy at 0 mph, and we’ve got a 4 ft swell pushing in from the south. The period is a short 6 seconds, so it’s a bit of a windswell, but the glassy conditions will make it look fun. The combined energy is moderate (291). Sunday morning is also strong: 4 ft from the ENE with a clean cross-offshore breeze, and the energy is a bit lower (269), but it’ll be clean. The following Monday morning, July 27th, keeps the good run going with 3 ft from the SSE and a long 10-second period, which is a nice combo for cleaner lines. The energy is moderate (300).

The very last good call is on the morning of Tuesday, July 28th. It’s tiny at 2 ft from the SSE with a 9-second period, but the wind is glassy, and the energy is still moderate (212). If you’re just looking for a paddle, it’s a winner.

The standout for the whole period is the Saturday morning, July 25th. That glassy, clean morning with the 4 ft south swell is the best on offer. The Sunday morning, July 26th, is a close second with that clean cross-offshore wind. For the rest of the second week, things get onshore and messy again.

So, to sum it up: the first week is a write-off. The second week has a few solid mornings starting July 21st, but the real gems are the glassy mornings on July 25th and 26th. Don’t sleep on those.

Rusty.

Short Range Forecast

Light rain (total 2mm), mostly falling on Thu night. Warm (max 28°C on Wed morning, min 25°C on Fri night). Wind will be generally light.

Days 4-6 Weather Summary

Mostly dry. Warm (max 28°C on Mon morning, min 24°C on Mon night). Wind will be generally light.

Wednesday
15
Thursday
16
Friday
17
Saturday
18
Sunday
19
Monday
20
Tuesday
21
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
0
0
0
0
0
0
0
0
1
0
0
0
1
0
2
2
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)
0.5
S
10
0.5
E
8
0.8
E
9
0.8
ESE
8
0.8
ESE
9
0.8
E
8
0.8
E
8
1.1
ESE
8
0.8
E
8
0.9
ESE
8
1
ESE
9
1.2
ESE
9
0.9
E
9
1
E
9
0.9
E
9
1
E
10
1.2
E
10
1.3
E
10
1.3
E
11
1.3
E
11
1.2
E
11
Wave Graph
Metric surfscale
Energy kJ
47
31
96
96
99
90
92
173
92
120
173
222
125
153
120
181
282
365
372
379
317
Wind (km/h)
15
SSW
20
S
25
SSW
15
SSW
20
S
10
SSW
20
SSE
20
SE
10
SE
10
SE
15
SE
10
S
15
SSW
20
S
15
SSW
10
S
15
SSW
15
NE
15
NE
20
ENE
20
E
Wind State
on
on
on
cross-on
on
on
on
cross-on
cross-on
cross-on
cross-on
on
on
on
on
on
on
cross-off
cross-off
cross-off
cross
High Tide
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
8:01AM1.17m
8:32PM1.33m
9:07AM1.04m
8:57PM1.32m
Low Tide
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
2:01PM0.57m
3:11AM0.58m
2:24PM0.72m
clear
clear
part cloud
part cloud
clear
rain showers
thunderstorm
part cloud
clear
part cloud
part cloud
clear
clear
clear
part cloud
part cloud
clear
part cloud
part cloud
part cloud
mod rain
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:33
4:35
4:35
4:35
4:37
4:37
4:37
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:52
6:52
6:52
6:52
6:51
6:51
6:50
 mm
1
1
8
Temp °C
28
28
27
28
28
27
27
27
25
27
27
25
27
27
26
28
28
26
26
26
25
Feels °C
31
31
29
31
30
31
30
29
28
29
29
28
29
28
30
31
31
32
28
28
28
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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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