Surf Forecasts:
Onjuku surf forecast from 21 Sep 2026:
- Best quality surf: Monday 21 Sep, 9PM (local time) - 20ft (6.0m), 13s period, SSE swell with offshore winds.
- Most powerful swell: Monday 21 Sep, 9PM (local time) - 20ft (6.0m), 13s period, SSE swell with 11,373 kJ wave energy.
- Next surfable swell (1★+): Monday 21 Sep, 9PM (local time) - 20ft (6.0m), 13s period with SSE 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 (Sep 21) at 9PM. The primary swell is predicted to be 6.0m and 13s period with a secondary swell of 2.0m and 10s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Onjuku in the next 16 days are 6.0m 13s and forecast to arrive on Monday (Sep 21) at 9PM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 5s period and expected on Monday (Sep 21) at 9PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Mon 21st Sep) | 20ft (6.0m) 13s |
| Best Surf | 9PM (Mon 21st Sep) | 20ft (6.0m) 13s |
| Most Powerful | 9PM (Mon 21st Sep) | 20ft (6.0m) 13s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
Short Range ForecastHeavy rain (total 113mm), heaviest during Mon afternoon. Warm (max 27°C on Mon afternoon, min 22°C on Wed night). Winds decreasing (near gales from the NNW on Mon night, calm by Wed night). | Days 5-7 Weather SummaryHeavy rain (total 38mm), heaviest during Sat night. Warm (max 24°C on Thu afternoon, min 21°C on Fri afternoon). Mainly fresh winds. | |||||||||||||||||||
Mon 21 | Tuesday 22 | Wednesday 23 | Thursday 24 | Friday 25 | Saturday 26 | Sunday 27 | ||||||||||||||
PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | |
Swell Height Map |  |  |  |  |  |  |  | |||||||||||||
Wave Height (m) Direction Period (s) | SE 11 | SSE 12 | SSE 9 | SSE 9 | SSE 8 | ENE 9 | ENE 9 | ENE 9 | ENE 9 | ENE 9 | ENE 8 | ENE 6 | ENE 6 | E 6 | E 7 | E 7 | E 7 | E 7 | E 7 | SSW 5 |
Wave Graph  | ||||||||||||||||||||
 kJ | 3991 | 5539 | 466 | 315 | 96 | 68 | 194 | 127 | 113 | 80 | 55 | 140 | 127 | 84 | 91 | 104 | 139 | 152 | 116 | 85 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-off | on | cross | cross-off | cross-off | cross-off | cross | off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | glassy |
High Tide | 3:28PM1.16m | 11:46PM1.11m | 3:22PM1.21m | 1:26AM1.17m | 3:32PM1.27m | 2:24AM1.25m | 3:45PM1.32m | 3:10AM1.33m | 4:01PM1.37m | 3:52AM1.40m | 4:19PM1.41m | 4:33AM1.43m | 4:37PM1.44m | |||||||
Low Tide | 8:11PM1.06m | 7:49AM0.43m | 8:35PM0.94m | 8:31AM0.37m | 9:01PM0.82m | 9:06AM0.34m | 9:27PM0.68m | 9:37AM0.33m | 9:55PM0.54m | 10:07AM0.37m | 10:24PM0.40m | 10:36AM0.43m | 10:55PM0.28m | |||||||
 |  |  |  | |  | | |  | |  | |  | | | |  | | | | |
 | — | — | 5:24 | — | — | 5:26 | — | — | 5:26 | — | — | 5:26 | — | — | 5:28 | — | — | 5:28 | — | — |
 | 5:37 | — | — | 5:36 | — | — | 5:35 | — | — | 5:34 | — | — | 5:31 | — | — | 5:30 | — | — | 5:29 | — |
mm | 86 | 16 | 3 | 3 | 1 | — | — | 4 | — | — | — | — | — | — | 1 | 3 | 30 | 4 | 2 | 16 |
Temp °C | 27 | 25 | 26 | 25 | 24 | 24 | 24 | 24 | 24 | 24 | 23 | 23 | 22 | 22 | 23 | 22 | 22 | 22 | 21 | 22 |
Feels °C | 24 | 20 | 28 | 27 | 24 | 22 | 23 | 25 | 24 | 24 | 23 | 20 | 19 | 21 | 22 | 21 | 21 | 22 | 21 | 23 |
Swell 1 Height (m) Direction Period (s) | S 13 | SSE 12 | SSE 9 | SSE 9 | SSE 8 | SSE 7 | SSE 6 | ENE 9 | ENE 9 | ENE 9 | ENE 8 | SSE 9 | SSE 8 | E 6 | E 7 | E 7 | E 7 | SSE 9 | E 7 | E 7 |
| kJ | 2833 | 5539 | 466 | 315 | 96 | 49 | 47 | 127 | 113 | 80 | 55 | 7 | 7 | 84 | 91 | 104 | 96 | 17 | 116 | 42 |
Swell 2 Height (m) Direction Period (s) | — | ESE 10 | ENE 9 | ENE 9 | NE 9 | ENE 9 | SSE 9 | SSE 9 | SE 5 | SSE 5 | SSE 8 | NE 8 | NE 8 | ENE 8 | ENE 8 | SSE 9 | SSE 10 | S 9 | SSE 9 | S 8 |
| kJ | — | 1072 | 108 | 127 | 81 | 68 | 8 | 7 | 29 | 10 | 7 | 3 | 3 | 12 | 14 | 8 | 19 | 14 | 26 | 12 |
Swell 3 Height (m) Direction Period (s) | — | SE 11 | E 13 | E 13 | — | SSE 9 | E 10 | SSE 8 | SSE 9 | SSE 8 | S 7 | S 7 | S 7 | SSE 8 | SE 8 | SE 13 | S 11 | S 12 | SE 12 | S 11 |
| kJ | — | 140 | 3 | 3 | — | 8 | 16 | 7 | 7 | 7 | 1 | 1 | 1 | 7 | 3 | 7 | 2 | 3 | 6 | 10 |
Wind waves Height (m) Direction Period (s) | SE 11 | NW 4 | — | NE 8 | ESE 4 | ENE 5 | ENE 9 | SE 6 | NNE 3 | NE 5 | NE 5 | ENE 6 | ENE 6 | ENE 6 | — | E 6 | E 7 | E 7 | SSE 5 | SSW 5 |
| kJ | 3991 | 34 | — | 129 | 32 | 56 | 194 | 52 | 1 | 23 | 32 | 140 | 127 | 82 | — | 78 | 139 | 152 | 20 | 85 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 574 | 75 | 9 | 51 | 51 | 903 | 1475 | 9 | 0 | 2279 | 240 | 964 | 2464 | 22 | 206 | 295 | 56 | 51 | 0 | 0 |
Best forecast wave conditions in Chiba | ||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Onjuku surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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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