Surf Forecasts:
Onjuku surf forecast from 9 Jul 2026:
- Best quality surf: Sunday 12 Jul, 9PM (local time) - 4.5ft (1.4m), 16s period, SSW swell with offshore winds.
- Most powerful swell: Saturday 11 Jul, 3AM (local time) - 7ft (2.2m), 17s period, S swell with 2,733 kJ wave energy.
- Next surfable swell (1★+): Sunday 12 Jul, 9PM (local time) - 4.5ft (1.4m), 16s period with SSW 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 Sunday (Jul 12) at 9PM. The primary swell is predicted to be 1.4m and 16s period with a secondary swell of 0.4m and 9s. Another secondary swell of 0.7m and 5s is also forecast. The wind is predicted to be offshore 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 3AM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Sun 12th Jul) | 4.5ft (1.4m) 16s |
| Best Surf | 9PM (Sun 12th Jul) | 4.5ft (1.4m) 16s |
| Most Powerful | 3AM (Sat 11th Jul) | 7ft (2.2m) 17s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
Alright, mates, Rusty here. Let’s take a look at what’s on offer for Onjuku over the next couple weeks.
Honestly, the first week is a bit of a write-off. We’ve got a big pulse of southerly swell pumping in from Thursday the 9th right through the weekend, but it’s all onshore or cross-onshore wind, so that 7ft of S swell is going to be a blown-out, choppy mess. The wave energy is massive – we’re talking 2703 (moderate to strong) on Saturday afternoon – but with strong winds from the SSW at 16 mph, only the most die-hard windsurfers would enjoy that. For us paddle surfers, it’s a full write-off. That combination is more interesting for kite surfing than paddle surfing.
Water temp is about 74°, which is a bit colder than normal for the time of year.
Then we get a bit of a reprieve on Monday the 13th. The swell drops right back to a clean 3ft from the SSW, and we get a light offshore breeze from the NNW at 6 mph. That’s a proper standout for the whole forecast period. Wave energy is weak at 423, but the wind is light and offshore, so the waves will be clean and lined up. Onjuku is inconsistent, so this is a nice little window if you’re keen for a paddle.
Tuesday the 14th morning keeps that clean vibe with 3ft from the S on a cross-offshore breeze at 9 mph, but the energy drops to 240. It’s small but rideable.
After that, it’s grim again. From Tuesday afternoon right through to the end of the third week, we’ve got very little to get excited about. The swell stays small – under 5ft – but the wind is either onshore or cross-onshore, with short-period wind swell (8 to 11 seconds). There’s a little spike on Thursday the 24th with 4ft from the ESE and a cross-offshore wind at 16 mph, but that’s about it. The wave energy is moderate (365) but the conditions are only marginal.
The standout window is the morning of Monday the 13th. It’s not going to be pumping, but with clean conditions and a wave that holds shape, it’s the only real game in town. After that, you’re waiting for a change in the pattern.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Sun morning. Warm (max 26°C on Fri morning, min 23°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryModerate rain (total 13mm), heaviest on Sun afternoon. Warm (max 26°C on Wed morning, min 22°C on Mon night). Wind will be generally light. | ||||||||||||||||||||
Thu 9 | Friday 10 | Saturday 11 | Sunday 12 | Monday 13 | Tuesday 14 | Wednesday 15 | |||||||||||||||
PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | |
Swell Height Map |  |  |  |  |  |  |  |  | |||||||||||||
Wave Height (m) Direction Period (s) | SSE 13 | S 14 | S 15 | S 16 | S 16 | S 16 | S 16 | SSW 16 | SSW 16 | SSW 16 | SSW 15 | SSW 13 | SSW 12 | SSW 12 | S 11 | S 11 | S 10 | ESE 8 | ESE 9 | ESE 9 | ESE 9 |
Wave Graph  | |||||||||||||||||||||
 kJ | 828 | 1663 | 1847 | 2369 | 2574 | 2632 | 2605 | 2241 | 1922 | 1611 | 696 | 372 | 192 | 186 | 192 | 58 | 98 | 75 | 147 | 186 | 207 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | on | on | on | on | cross-on | cross-on | cross-on | off | off | cross-off | off | cross-off | cross-on | cross-on | cross-on | on | on | cross-on |
High Tide | 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 | 4:33AM1.52m | ||||||||
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 | 11:51AM-0.03m | |||||||
 |  |  | | | | |  |  |  |  |  | |  | | | | | | | | |
 | — | — | 4:31 | — | — | 4:31 | — | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:35 |
 | 6:54 | — | — | 6:54 | — | — | 6:54 | — | — | 6:53 | — | — | 6:53 | — | — | 6:53 | — | — | 6:52 | — | 6:52 |
mm | — | — | — | — | — | — | — | — | 2 | 8 | 2 | 1 | 1 | — | — | 1 | — | — | — | — | — |
Temp °C | 25 | 24 | 26 | 25 | 24 | 25 | 25 | 24 | 25 | 25 | 24 | 25 | 25 | 23 | 25 | 25 | 24 | 26 | 26 | 25 | 27 |
Feels °C | 26 | 27 | 27 | 26 | 26 | 26 | 25 | 25 | 26 | 26 | 27 | 27 | 27 | 26 | 27 | 27 | 26 | 29 | 28 | 28 | 29 |
Swell 1 Height (m) Direction Period (s) | SSE 13 | S 14 | S 15 | S 16 | S 16 | S 16 | S 16 | SSW 16 | SSW 16 | SSW 16 | SSW 15 | SSW 13 | SSW 12 | SSW 12 | S 11 | E 9 | S 10 | ESE 8 | ESE 9 | ESE 9 | ESE 9 |
| kJ | 828 | 1663 | 1847 | 2369 | 2574 | 2632 | 2605 | 2241 | 1922 | 1611 | 696 | 372 | 192 | 186 | 192 | 39 | 98 | 75 | 147 | 186 | 207 |
Swell 2 Height (m) Direction Period (s) | S 15 | ESE 8 | ESE 8 | ESE 10 | E 9 | E 9 | E 9 | E 9 | E 9 | E 9 | SSW 5 | ESE 9 | ESE 9 | ESE 9 | ESE 9 | S 11 | ESE 9 | S 10 | SSW 10 | SSW 9 | SSW 9 |
| kJ | 545 | 85 | 65 | 107 | 60 | 59 | 40 | 40 | 39 | 40 | 20 | 27 | 27 | 26 | 26 | 58 | 62 | 49 | 31 | 16 | 8 |
Swell 3 Height (m) Direction Period (s) | ESE 8 | E 8 | NE 8 | — | ESE 9 | — | E 9 | SSE 9 | SE 11 | SE 10 | ESE 9 | SE 10 | SW 14 | SE 5 | SE 12 | SE 12 | SE 10 | SE 10 | SE 13 | S 13 | S 14 |
| kJ | 85 | 100 | 2 | — | 90 | — | 58 | 35 | 29 | 27 | 26 | 24 | 54 | 4 | 22 | 35 | 25 | 32 | 7 | 3 | 4 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | SSW 4 | SSW 4 | SW 5 | — | — | — | — | S 6 | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | 8 | 28 | 37 | — | — | — | — | 33 | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 88 | 88 | 18 | 0 | 0 | 0 | 0 | 0 | 73 | 9 | 9 | 9 | 9 | 17 |
Best forecast wave conditions in Chiba | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
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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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