Surf Forecasts:
Onjuku surf forecast from 26 Jul 2026:
- Best quality surf: Tuesday 28 Jul, 6AM (local time) - 3.5ft (1.1m), 7s period, NE swell with offshore winds.
- Most powerful swell: Sunday 2 Aug, 3PM (local time) - 3ft (0.9m), 13s period, SE swell with 261 kJ wave energy.
- Next surfable swell (1★+): Sunday 26 Jul, 9PM (local time) - 1.5ft (0.4m), 14s period with SE 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 26) at 9PM. The primary swell is predicted to be 0.4m and 14s period with a secondary swell of 0.8m and 6s. Another secondary swell of 0.5m and 10s 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 0.9m 13s and forecast to arrive on Sunday (Aug 02) at 3PM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.9m 6s period and expected on Monday (Jul 27) at 6PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Sun 26th Jul) | 1.5ft (0.4m) 14s |
| Best Surf | 6AM (Tue 28th Jul) | 3.5ft (1.1m) 7s |
| Most Powerful | 3PM (Sun 2nd Aug) | 3ft (0.9m) 13s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
The Lowdown
G’day, Rusty here. Let’s be straight with you about Onjuku. The next week and a half is a bit of a write-off for decent waves. We’ve got a real rough patch ahead, but the long-range offers up something serious if you’re patient and skilled.
The first solid surf to speak of doesn’t roll in until Sunday, 3rd August. Before that, from now through Saturday, 2nd August, we’re looking at a long dry spell. The swell is tiny, the wind is messy, and the energy is weak. There’s just nothing worth paddling out for. It’s a proper gap in the action.
Alright, let’s talk about the real show. From Sunday, 3rd August through to Monday, 10th August, Onjuku gets absolutely hammered by a massive, long-period groundswell from the Southeast. The combined energy skyrockets from moderate (1468) up to an insane 18110 by Friday, 7th August. This is a very strong swell event. The swell heights start at 6 ft and climb to a monstrous 20 ft by Friday morning. The period is a very long 16 to 17 seconds – that’s pure groundswell, meaning it’ll have heaps of power and long lulls between sets. These conditions are strictly for experienced surfers only. Anything over 8 ft is expert territory, and we’re way past that. The cross-offshore winds from the NE will keep things clean, but the sheer size is the main story. By Wednesday, 5th August, the swell hits 10 ft to 12 ft, and from Thursday, 6th August onward, it’s 15 ft to 20 ft. This is too big for this break, even for the crew who know what they’re doing. The best chance for a safe, powerful wave in that period might be the Sunday, 9th August morning, when the swell drops to 10 ft, the wind goes glassy, and the conditions are described as excellent for experienced surfers. That’s a standout moment, but it’s still a heavy wave.
Water temperature sits at 80°F, which is 0.5°F warmer than average for this time of year, so nothing unusual there.
The later part of the run, from Monday, 10th August, sees the swell still big at 8 ft to 10 ft, but onshore winds from the South spoil the quality. The energy is still very strong (over 3000), but the onshore wind will chop it up.
So, to sum it up: don’t waste your time until Sunday, 3rd August. After that, it’s a massive, powerful, and dangerous swell for experts only. If you’re an experienced surfer, the Sunday, 9th August morning looks like the best window for a clean, glassy, but still very large wave. For everyone else, sit this one out.
Rusty.
Short Range ForecastHeavy rain (total 36mm), heaviest during Sun night. Warm (max 28°C on Sun morning, min 23°C on Sun night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 30°C on Fri morning, min 24°C on Wed night). Wind will be generally light. | ||||||||||||||||||||
Sunday 26 | Monday 27 | Tuesday 28 | Wednesday 29 | Thursday 30 | Friday 31 | Saturday 1 | |||||||||||||||
AM | 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) | ENE 7 | E 7 | SE 14 | SE 10 | ENE 7 | ENE 7 | ENE 8 | E 7 | E 7 | SE 10 | SSW 7 | ENE 7 | ENE 8 | ENE 8 | ENE 7 | SE 9 | SSW 7 | S 6 | ESE 11 | ESE 10 | SE 13 |
Wave Graph  | |||||||||||||||||||||
 kJ | 114 | 74 | 72 | 51 | 99 | 99 | 102 | 70 | 37 | 44 | 43 | 57 | 67 | 66 | 43 | 30 | 47 | 31 | 38 | 33 | 80 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | off | cross-off | cross-off | cross-off | cross | on | cross-off | cross-off | cross | cross-off | cross | on | cross-on | cross | cross | cross | cross-off | cross-off | cross-off |
High Tide | 4:42PM1.19m | 1:35AM1.28m | 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 | ||||||||
Low Tide | 8:40PM1.07m | 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 | ||||||||
 |  |  | |  |  | | | | | |  | | | | | | |  | | | |
 | 4:41 | — | — | 4:43 | — | — | 4:43 | — | — | 4:43 | — | — | 4:45 | — | — | 4:46 | — | — | 4:46 | — | — |
 | — | 6:46 | — | — | 6:45 | — | — | 6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:42 | — |
mm | — | 2 | 21 | — | — | 2 | 5 | 1 | 5 | — | — | — | — | — | — | — | — | — | 1 | — | — |
Temp °C | 28 | 28 | 26 | 27 | 25 | 24 | 26 | 28 | 25 | 27 | 26 | 25 | 28 | 28 | 27 | 30 | 28 | 26 | 27 | 27 | 25 |
Feels °C | 32 | 32 | 31 | 27 | 25 | 27 | 29 | 30 | 28 | 29 | 28 | 28 | 31 | 30 | 30 | 34 | 32 | 30 | 28 | 29 | 27 |
Swell 1 Height (m) Direction Period (s) | ENE 7 | E 7 | E 6 | SE 10 | SE 10 | ENE 7 | ENE 8 | E 7 | E 7 | ENE 7 | SSW 7 | ENE 7 | ENE 8 | ENE 8 | ENE 7 | SSW 6 | SSW 7 | S 6 | S 6 | S 6 | ESE 10 |
| kJ | 114 | 74 | 38 | 51 | 63 | 99 | 102 | 70 | 37 | 25 | 34 | 57 | 67 | 66 | 43 | 24 | 47 | 31 | 17 | 18 | 51 |
Swell 2 Height (m) Direction Period (s) | SE 10 | SE 10 | SE 10 | NE 10 | S 8 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | SSW 7 | SE 9 | SE 9 | SE 9 | ENE 7 | ENE 7 | ENE 7 | ESE 11 | ESE 10 | S 6 |
| kJ | 54 | 64 | 51 | 28 | 34 | 63 | 49 | 35 | 35 | 44 | 32 | 18 | 31 | 31 | 31 | 30 | 17 | 17 | 38 | 33 | 19 |
Swell 3 Height (m) Direction Period (s) | SE 15 | SE 15 | SE 14 | SSW 8 | SE 14 | SSW 8 | SSW 8 | SSW 8 | SSW 8 | SSW 6 | SE 12 | SE 9 | SSW 7 | ESE 12 | E 12 | SE 9 | SE 9 | SE 9 | SE 9 | SE 8 | SE 13 |
| kJ | 55 | 54 | 72 | 24 | 47 | 22 | 24 | 24 | 23 | 20 | 23 | 31 | 18 | 14 | 11 | 30 | 22 | 13 | 12 | 11 | 80 |
Wind waves Height (m) Direction Period (s) | — | — | — | ENE 6 | ENE 7 | — | — | — | SW 3 | NNE 4 | NE 6 | — | — | S 7 | SSW 3 | — | E 4 | — | — | — | — |
| kJ | — | — | — | 39 | 99 | — | — | — | 2 | 7 | 43 | — | — | 28 | 9 | — | 6 | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 9 | 9 | 0 | 16 | 56 | 0 | 12 | 9 | 0 | 0 | 57 | 0 | 9 | 9 | 17 | 2 | 143 | 554 | 206 | 579 | 56 |
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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