Surf Forecasts:
Onjuku surf forecast from 11 Jul 2026:
- Best quality surf: Monday 13 Jul, 6AM (local time) - 3.5ft (1.0m), 13s period, SSW swell with glassy winds.
- Most powerful swell: Sunday 12 Jul, 9AM (local time) - 6.5ft (2.0m), 16s period, SSW swell with 1,993 kJ wave energy.
- Next surfable swell (1★+): Monday 13 Jul, 6AM (local time) - 3.5ft (1.0m), 13s 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 Monday (Jul 13) at 6AM. The primary swell is predicted to be 1.0m and 13s period with a secondary swell of 1.0m and 6s. Another secondary swell of 1.3m and 6s 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 2.0m 16s and forecast to arrive on Sunday (Jul 12) at 9AM. 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+) | 6AM (Mon 13th Jul) | 3.5ft (1.0m) 13s |
| Best Surf | 6AM (Mon 13th Jul) | 3.5ft (1.0m) 13s |
| Most Powerful | 9AM (Sun 12th Jul) | 6.5ft (2.0m) 16s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
Hey, Rusty here. Let’s talk about Onjuku over the next 16 days. This stretch is a real mixed bag – mostly poor surf, with a couple of golden windows that’ll make you glad you waited. The spot is inconsistent, so when it does line up, you’ve got to jump.
First up, Sunday July 12 is a write-off – messy cross-on wind, 7ft SSW swell but choppy and ugly. No go. Monday July 13 starts marginal in the morning with 3ft SSW swell and light cross-on, but the afternoon turns glassy. That’s the standout of the first week: 3ft S swell, 12-second period, moderate wave energy (325). It’s clean, small, and perfect for intermediates. The water temp is about average for the season – nothing weird. Tuesday July 14 has a brief window in the morning with 2ft SSW swell and cross-off wind, but it’s only 1/10 so keep expectations low. Then the rest of the week is a washout – onshore winds, weak short-period junk, and poor conditions. Even Saturday July 18 brings a bigger 7ft SSE swell, but it’s cross-on and choppy, so more of a kite session than a paddle.
Into the second week, things stay quiet until Saturday July 25. That morning shapes up nicely: 3ft SE swell, 10-second period, light cross-off wind, clean conditions, and moderate wave energy (313). It’s a promising little window, though it’s still a week and a half away so don’t lock it in. Sunday July 26 has a cross-off wind too but swell is smaller and more marginal. Monday July 27 morning shows a 4ft ESE swell with a very long 16-second period and cross-off wind – that’s a groundswell with real power (935 energy). But it’s only rated marginal, likely due to tide or break shape, so only experts should get excited. That long period might make it break too straight at Onjuku’s beach, but if you’re picky, it’s worth a look.
Best bet: Monday July 13 afternoon. That glassy, clean little swell is your moment. Second choice: Saturday July 25 morning, if the forecast holds. Stay patient.
Rusty
Short Range ForecastLight rain (total 9mm), mostly falling on Sun night. Warm (max 28°C on Mon morning, min 23°C on Mon night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 28°C on Fri morning, min 24°C on Tue night). Wind will be generally light. | ||||||||||||||||||||
Sunday 12 | Monday 13 | Tuesday 14 | Wednesday 15 | Thursday 16 | Friday 17 | Sat 18 | |||||||||||||||
Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | |
Swell Height Map |  |  |  |  |  |  |  |  | |||||||||||||
Wave Height (m) Direction Period (s) | SSW 16 | SSW 16 | SSW 16 | SSW 14 | SSW 13 | S 12 | SSW 11 | SSW 11 | SSW 10 | ESE 10 | S 10 | E 8 | ESE 8 | ESE 9 | ESE 8 | E 8 | ESE 9 | ESE 9 | SSE 8 | SSE 12 | SSE 11 |
Wave Graph  | |||||||||||||||||||||
 kJ | 1892 | 1993 | 1224 | 651 | 294 | 294 | 170 | 123 | 86 | 64 | 50 | 71 | 120 | 126 | 125 | 86 | 101 | 106 | 142 | 1215 | 757 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | cross-on | glassy | cross-off | cross-off | cross | glassy | cross-on | on | cross-on | on | on | on | cross-on | cross | cross | cross-on | cross-on |
High Tide | 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 | 6:54PM1.36m | 5:24AM1.49m | 7:20PM1.34m | 6:15AM1.41m | ||||||||
Low Tide | 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 | 11:55PM0.87m | 12:29PM0.08m | 00:40AM0.77m | 1:04PM0.23m | ||||||||
 |  | |  |  | | | | | |  | |  | | | | | |  |  | | |
 | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:35 | — | — | 4:35 | — | — | 4:35 | — |
 | 6:54 | — | 6:53 | — | — | 6:53 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | — | 6:52 | — | — | 6:52 |
mm | — | — | — | 9 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 8 | 5 | 1 |
Temp °C | 25 | 26 | 26 | 26 | 28 | 28 | 26 | 26 | 25 | 25 | 27 | 27 | 26 | 27 | 27 | 25 | 28 | 28 | 26 | 27 | 28 |
Feels °C | 25 | 27 | 28 | 29 | 31 | 31 | 30 | 29 | 29 | 29 | 29 | 28 | 28 | 28 | 29 | 27 | 31 | 31 | 30 | 30 | 30 |
Swell 1 Height (m) Direction Period (s) | SSW 16 | SSW 16 | SSW 16 | SSW 14 | SSW 13 | S 12 | SSW 11 | SSW 11 | SSW 10 | ESE 10 | E 8 | E 8 | ESE 8 | ESE 9 | ESE 8 | E 8 | ESE 9 | ESE 9 | SSE 8 | SSE 12 | SSE 11 |
| kJ | 1892 | 1993 | 1224 | 651 | 294 | 294 | 170 | 123 | 86 | 64 | 50 | 71 | 120 | 126 | 125 | 86 | 101 | 106 | 142 | 1215 | 757 |
Swell 2 Height (m) Direction Period (s) | E 9 | E 9 | E 9 | S 5 | S 6 | ESE 9 | ESE 9 | ESE 9 | ESE 9 | S 10 | S 10 | SSW 9 | SE 11 | S 13 | SE 11 | SE 10 | SE 9 | SSE 9 | E 8 | E 8 | E 9 |
| kJ | 40 | 40 | 40 | 24 | 43 | 16 | 16 | 25 | 17 | 51 | 47 | 28 | 5 | 3 | 18 | 23 | 22 | 56 | 88 | 57 | 78 |
Swell 3 Height (m) Direction Period (s) | SSE 9 | SE 10 | SE 10 | ESE 9 | ESE 9 | SE 10 | SSE 10 | SE 12 | SE 12 | — | SE 10 | SSE 11 | S 13 | SE 11 | S 12 | SSW 8 | SSW 8 | SSE 8 | SSE 15 | SSW 8 | SW 7 |
| kJ | 35 | 28 | 26 | 27 | 27 | 15 | 9 | 22 | 22 | — | 16 | 12 | 4 | 5 | 3 | 7 | 6 | 23 | 86 | 6 | 2 |
Wind waves Height (m) Direction Period (s) | SSW 4 | SSW 5 | SSW 5 | SSW 5 | — | — | — | — | — | — | SW 2 | SSW 3 | SSW 9 | SSW 4 | SSW 4 | S 4 | SSW 4 | — | — | — | — |
| kJ | 26 | 33 | 23 | 50 | — | — | — | — | — | — | 1 | 6 | 84 | 25 | 34 | 23 | 5 | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 101 | 88 | 536 | 18 | 2 | 0 | 0 | 0 | 9 | 0 | 9 | 9 | 17 | 9 | 9 | 9 | 9 | 9 | 17 | 51 | 91 |
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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