Onjuku Surf Break

Lat Long: 35.18° N 140.35° E

Onjuku Surf Forecast and Surf Report

Issued: 8 am 23 Jul 2026 (local time)

Forecast update in  hr  min

Today's Onjuku sea temperature is
25.9° 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 23 Jul 2026:

  • Best quality surf: Thursday 30 Jul, 3AM (local time) - 3ft (0.9m), 7s period, NE swell with cross-offshore winds.
  • Most powerful swell: Monday 27 Jul, 6PM (local time) - 3.5ft (1.1m), 6s period, SSW swell with 104 kJ wave energy.
  • Next surfable swell (1★+): Thursday 23 Jul, 6PM (local time) - 2.5ft (0.7m), 9s 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 6PM. The primary swell is predicted to be 0.7m and 9s period with a secondary swell of 0.4m and 6s. 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 1.1m 6s and forecast to arrive on Monday (Jul 27) at 6PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 5s period and expected on Tuesday (Jul 28) at 12PM.

Wave TypeTime (JST) & Date Wave Height & Period
Next good surf (1 star+) 6PM (Thu 23rd Jul)2.5ft (0.7m) 9s
Best Surf 3AM (Thu 30th Jul)3ft (0.9m) 7s
Most Powerful 6PM (Mon 27th Jul)3.5ft (1.1m) 6s

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


The Lowdown

Alright folks, it’s Rusty here. Let’s take a look at the local lineup.

First off, the next week and a half is going to be a real struggle. We’ve got a long stretch of poor to ordinary conditions on the cards. The first solid recommendation doesn’t pop up until Saturday, 1st August, so be prepared for a rough run—this is one of those patches where the ocean just isn’t playing ball for paddle surfing.

The standout window is Saturday morning, 1st August at Onjuku. The swell is building from the ESE at 2ft, and it’s carrying some decent energy (252). The wind is light from the ENE, keeping it cross-offshore and clean. It’s still small, and the period is a solid 16 seconds, so those long-period groundswell lines will have plenty of punch. That long period can make it a bit tricky at a beach break—it tends to straighten out—but the light wind and clean surface make it the best option by a long shot. The water temp is sitting at 79°, which is pretty much bang on average for this time of year, so no surprises there.

Right after that, Sunday morning, 2nd August, the swell jumps up to 5ft from the ESE with a 17-second period, and the combined energy is already strong (1449). The wind is light from the east, but it’s cross-shore, so there’ll be some small ripples on the face. With the size getting over 5ft, it’s starting to push out of beginner territory, but it’s still manageable for the intermediates. The long period is a plus for wave quality, but again, watch for it closing out at this beach.

Then things get wild. By Monday, 3rd August, the swell is 10ft from the ESE, and the energy is massive (5643). That’s well into the big stuff—only for experienced surfers, and even then, the onshore wind from the SSW is going to chop it up. The whole first week of August is dominated by strong, messy swell with cross-onshore winds. Honestly, for a beach setup like this, it’s looking more interesting for kite surfing than paddle surfing through that period.

The very last glimmer of hope is Friday morning, 7th August. The swell has dropped to 5ft from the east, but the wind is glassy (SW light air), and the energy is still moderate (726). The period is 11 seconds, so it’s a solid, clean wave. The only catch? It’s a risk of thunderstorms, so keep an eye on the sky. Still, that’s the cleanest, most user-friendly wave of the whole forecast.

Remember, Onjuku is inconsistent and can be a bit of a gamble, but when it lines up with light wind and a long-period groundswell, it’s worth the paddle. The standout is clearly that Saturday morning, 1st August—small, clean, and your best bet in a long, frustrating stretch.

Rusty, signing off.

Short Range Forecast

Moderate rain (total 18mm), heaviest on Sat night. Warm (max 29°C on Thu morning, min 23°C on Sat night). Wind will be generally light.

Days 4-6 Weather Summary

Heavy rain (total 22mm), heaviest during Tue afternoon. Warm (max 27°C on Sun afternoon, min 21°C on Tue night). Wind will be generally light.

Thursday
23
Friday
24
Saturday
25
Sunday
26
Monday
27
Tuesday
28
Wednesday
29
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
AM
PM
Night
Rating
(10 max)
1
0
1
1
0
0
0
0
1
1
0
0
1
1
0
0
0
1
0
0
1
Swell
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Height Map
Wave
Height (m)
Direction
Period (s)
0.7
E
10
0.7
E
9
0.6
E
9
0.6
E
9
0.5
SE
11
0.5
SE
10
0.5
SE
10
0.4
SE
16
0.5
SE
10
0.4
SE
15
0.4
SE
15
0.4
SE
14
0.9
SSW
6
1.1
SSW
6
0.6
SE
10
0.5
SE
10
0.5
SE
10
0.5
SE
10
0.5
SE
10
0.5
SE
9
0.4
SE
10
Wave Graph
Metric surfscale
Energy kJ
87
81
58
57
57
51
48
63
50
55
64
72
58
101
63
49
48
47
45
43
32
Wind (km/h)
10
NE
15
ENE
15
NE
15
ENE
15
ESE
10
SSE
5
ESE
10
ESE
15
NE
10
ENE
5
SW
10
SSW
5
NNE
20
ENE
25
NE
20
NE
25
NNE
20
N
25
NNE
25
NE
15
NNE
Wind State
cross-off
cross-off
cross-off
cross-off
cross
on
cross
cross-on
cross-off
cross-off
cross-on
cross-on
off
cross-off
cross-off
cross-off
cross-off
off
cross-off
cross-off
cross-off
High Tide
10:06PM1.28m
11:05PM1.26m
4:30PM1.13m
00:24AM1.25m
4:42PM1.19m
1:35AM1.28m
5:00PM1.23m
2:32AM1.33m
5:21PM1.27m
3:19AM1.38m
5:42PM1.30m
Low Tide
6:45AM0.44m
7:51AM0.37m
7:16PM1.10m
8:43AM0.30m
8:40PM1.07m
9:26AM0.23m
9:28PM1.02m
10:04AM0.17m
10:04PM0.97m
10:37AM0.13m
10:38PM0.90m
clear
clear
thunderstorm
part cloud
part cloud
part cloud
thunderstorm
part cloud
thunderstorm
thunderstorm
thunderstorm
rain showers
thunderstorm
thunderstorm
part cloud
light rain
mod rain
rain showers
part cloud
clear
clear
<span class="translation_missing" title="translation missing: en.weather_tables.sunrise">Sunrise</span>
4:39
4:39
4:41
4:41
4:43
4:43
4:43
<span class="translation_missing" title="translation missing: en.weather_tables.sunset">Sunset</span>
6:49
6:47
6:47
6:46
6:45
6:45
6:45
 mm
2
1
15
2
3
1
1
1
4
8
2
Temp °C
29
29
27
28
28
26
28
28
24
26
27
27
27
27
25
23
22
22
25
25
23
Feels °C
33
32
31
32
32
29
32
32
26
30
32
31
31
27
26
23
21
22
24
23
23
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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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