Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 2 am 27 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
26.9° C
0.8° 

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


Onjuku surf forecast from 26 Jul 2026:

  • Best quality surf: Sunday 2 Aug, 6PM (local time) - 4.5ft (1.3m), 14s period, SE swell with cross-offshore winds.
  • Most powerful swell: Monday 3 Aug, 9AM (local time) - 6ft (1.9m), 17s period, SE swell with 1,961 kJ wave energy.
  • Next surfable swell (1★+): Monday 27 Jul, 9PM (local time) - 4.5ft (1.3m), 7s period with NE 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 27) at 9PM. The primary swell is predicted to be 1.3m and 7s period with a secondary swell of 1.0m and 7s. Another secondary swell of 0.6m and 10s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.

The most powerful waves expected at Onjuku in the next 16 days are 1.9m 17s and forecast to arrive on Monday (Aug 03) at 9AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.4m 6s period and expected on Monday (Jul 27) at 12PM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 9PM (Mon 27th Jul)4.5ft (1.3m) 7s
Best Surf 6PM (Sun 2nd Aug)4.5ft (1.3m) 14s
Most Powerful 9AM (Mon 3rd Aug)6ft (1.9m) 17s

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


The Lowdown

G’day, I’m Rusty. Let’s talk about what’s coming up at Onjuku—it’s a bit of a mixed bag, but there’s some interesting stuff on the horizon if you’re patient.

Right now, the first solid surf recommendation kicks off on Monday, 27th July. To be honest, the early part of the week is pretty average. Monday morning you’ve got a small 1.6 ft swell from the SE with a short period, only 10 seconds, and the combined energy is weak (126). The wind is cross-off from the NNE at 15.5 mph, so it’s messy and not worth paddling out. Monday afternoon picks up a bit to 3.9 ft from the NE, but that’s a short, weak period (6 seconds) and cross-off wind at 15.5 mph too. The water temp is 80.4°, which is about normal for this time of year.

Tuesday (28th) is similar: Tuesday morning has 3.0 ft ENE swell, period 8 seconds, cross wind from the E at 6.2 mph. It’s not great. The small swell and light cross wind just don’t make for good waves. Tuesday afternoon is even worse with 2.6 ft and onshore wind.

Wednesday and Thursday (29th and 30th) stay small and ordinary. Wednesday morning (3.0 ft, SSW, period 7 seconds, cross-off wind) is surfable but nothing to write home about. Thursday morning has 2.3 ft, NE, period 8 seconds, and cross-off wind. The energy remains low across the board—most readings are between 100 and 150—so the waves will be weak and unexciting.

Friday (31st) through Saturday (1st August) the swell drops even further. 1.6 ft to 2.0 ft, period 8 seconds, energy dropping to 65 on Saturday morning. It’s all cross-off wind, light, but the waves are just too small to get excited about.

Now, here’s where things get interesting. Sunday, 2nd August, the swell picks up and turns into something worth watching. Sunday morning has 2.0 ft from the SE but check the period: 15 seconds! That’s groundswell, with moderate combined energy (287). The wind is cross-off from the ENE at 9.3 mph, so it’s clean. Sunday afternoon jumps to 3.6 ft from the SE, period 14 seconds, and the energy is getting solid at 576. This is the first decent window in ages. The water is still around 80.4°, which is average for the season.

Monday, 3rd August, sees a jump to 6.2 ft from the SE (period 17 seconds) and energy is ramping up to 2025. But there’s a catch—the wind shifts to cross-shore from the E at 9.3 mph and there’s light rain. The surf is marginal due to tide and conditions, but the swell is real and the period is very long (17 seconds). At 6.2 ft it’s still manageable for intermediates, but the long period makes it better suited for a point or reef setup than a beach break like Onjuku, which can get a bit straight and closed out.

Now, this is where it gets wild. Tuesday, 4th August, the swell explodes. Tuesday morning you’ve got a solid 9.8 ft from the ESE, period 17 seconds, and the combined energy is a massive 5287—that’s strong. The wind is cross-off from the NE at 6.2 mph and the conditions are clean. But let’s be real: 9.8 ft is expert territory, especially with that very long period. It’s going to be big, powerful, and no place for beginners. This is the standout for experienced surfers only.

Tuesday afternoon (4th) and Wednesday morning (5th) get even bigger: 11.5 ft from the ESE, period 16-17 seconds, energy up to 6779 and 5522. Wednesday morning is glassy with NE wind at just 3.1 mph—gorgeous conditions—but the swell is too big for the break, and the forecast says the same. This is for big-wave chargers only.

Thursday, 6th August, stays massive: 11.5 ft to 13.1 ft overnight, period 16-17 seconds, energy peaking at 9478. The wind is cross to cross-onshore, not ideal, but the power is unreal. Again, this is too big for paddling at Onjuku. Friday (7th) keeps growing: 16.4 ft to 19.7 ft, period 18 seconds, energy over 25000. That’s enormous. Onshore to cross-onshore wind from the SE. By Saturday (8th), we’re talking 27.9 ft with onshore wind and 850

Short Range Forecast

Moderate rain (total 10mm), heaviest on Mon morning. Warm (max 27°C on Tue morning, min 23°C on Mon morning). Wind will be generally light.

Days 4-6 Weather Summary

Light rain (total 4mm), mostly falling on Thu afternoon. Warm (max 27°C on Thu morning, min 24°C on Fri night). Wind will be generally light.

Monday
27
Tuesday
28
Wednesday
29
Thursday
30
Friday
31
Saturday
1
Sunday
2
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
1
1
0
0
0
1
0
1
1
0
1
1
1
1
1
1
1
2
2
2
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.4
SE
14
1.2
NE
6
1
ENE
8
0.9
ENE
8
0.8
ENE
8
0.4
SE
10
0.9
SSW
7
0.8
SSW
7
0.6
SSW
7
0.7
NE
8
0.8
ENE
8
0.8
ENE
8
0.7
ENE
8
0.7
ENE
8
0.6
ENE
8
0.5
ENE
8
0.6
ESE
10
0.6
ESE
10
0.6
SE
15
1.1
SE
14
1.4
SE
14
Wave Graph
Metric surfscale
Energy kJ
51
112
117
99
75
35
66
63
42
64
71
73
55
54
43
40
61
64
181
529
799
Wind (km/h)
25
NNE
25
NE
15
NNE
10
E
20
S
20
WSW
10
ENE
10
ESE
15
ENE
15
ENE
10
ESE
10
ENE
10
ENE
10
ENE
0
NNW
10
NE
15
ENE
15
NE
15
ENE
15
E
15
ESE
Wind State
cross-off
cross-off
cross-off
cross
on
cross
cross-off
cross
cross-off
cross-off
cross-on
cross-off
cross-off
cross-off
glassy
cross-off
cross-off
cross-off
cross-off
cross-off
cross
High Tide
5:00PM1.23m
2:32AM1.33m
5:21PM1.27m
3:19AM1.38m
5:42PM1.30m
4:01AM1.42m
6:03PM1.32m
4:41AM1.43m
6:23PM1.34m
5:20AM1.41m
6:44PM1.36m
6:00AM1.37m
7:05PM1.38m
Low Tide
9:26AM0.23m
9:28PM1.02m
10:04AM0.17m
10:04PM0.97m
10:37AM0.13m
10:38PM0.90m
11:08AM0.12m
11:11PM0.83m
11:38AM0.14m
11:45PM0.75m
12:06PM0.20m
00:21AM0.68m
12:33PM0.28m
00:59AM0.61m
rain showers
clear
part cloud
part cloud
thunderstorm
thunderstorm
clear
clear
part cloud
part cloud
thunderstorm
part cloud
cloud
thunderstorm
thunderstorm
part cloud
part cloud
rain showers
part cloud
part cloud
mod rain
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:43
4:43
4:43
4:45
4:46
4:46
4:47
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:45
6:45
6:45
6:44
6:43
6:42
6:40
 mm
5
1
4
1
1
1
1
7
Temp °C
25
24
24
27
27
27
27
27
25
27
27
25
26
26
25
26
26
25
27
27
25
Feels °C
24
24
26
30
28
28
29
30
28
30
30
28
30
29
29
29
28
28
29
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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