
Surf Forecasts:
Onjuku surf forecast from 20 Jul 2026:
- Best quality surf: Wednesday 22 Jul, 9AM (local time) - 3.5ft (1.0m), 10s period, E swell with glassy winds.
- Most powerful swell: Tuesday 21 Jul, 12AM (local time) - 4ft (1.2m), 11s period, E swell with 329 kJ wave energy.
- Next surfable swell (1★+): Wednesday 22 Jul, 9AM (local time) - 3.5ft (1.0m), 10s 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 Wednesday (Jul 22) at 9AM. The primary swell is predicted to be 1.0m and 10s period with a secondary swell of 0.5m and 5s. Another secondary swell of 0.7m and 5s 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 1.2m 11s and forecast to arrive on Tuesday (Jul 21) at 12AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 3s period and expected on Friday (Jul 24) at 3AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Wed 22nd Jul) | 3.5ft (1.0m) 10s |
| Best Surf | 9AM (Wed 22nd Jul) | 3.5ft (1.0m) 10s |
| Most Powerful | 12AM (Tue 21st Jul) | 4ft (1.2m) 11s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s coming up for Onjuku over the next couple of weeks.
It’s a pretty quiet start, I’m not gonna lie. The first few days are a bit of a write-off with messy, choppy conditions and onshore winds messing things up. The magic starts to happen on Wednesday morning, the 22nd of July. That’s your first real window. We’ve got a 3ft swell from the east with a 10-second period, and the wind is basically glassy. That’s clean, clean surf. The combined energy is moderate (239), and it’s the kind of morning where you just want to be out there with a log. Don’t expect it to be pumping, but it’ll be fun and tidy.
Thursday the 23rd is similar, but smaller. We’re looking at 3ft to 2ft from the east, and again glassy conditions in the morning. It’s ordinary, but if you’re desperate for a paddle, it’s surfable. The energy drops a bit (147 to 114), so it’s getting weak.
After that, things get a bit patchy. There’s a stretch of small, clean waves from the 24th to the 27th, with swell heights under 2ft and periods all over the place. The wind is mostly cross-offshore or glassy, so the surface will be clean, but the waves are tiny. The combined energy is low (around 128 to 165), so it’s more of a longboard or a swim.
Now, the real standout is Monday afternoon, the 27th of July. The swell jumps a bit to 4ft from the SSW, but the period is a short 5 seconds. Wind is clean though. The energy bumps up to 226. It’s a bit of a mixed bag – short period swell like that doesn’t always hold up well, but it’s something to keep an eye on.
Then we hit a rough patch. From the 28th of July through to the 31st, the wind turns onshore and gets strong. Swell builds, hitting 5ft to 10ft, but the wind is cross-on or onshore, turning it into a choppy, lumpy mess. The energy is moderate to strong (260 to 3413), but the quality is poor. This is not paddle surf – if you’re a kite surfer, this setup might be more your thing.
The first week of August has a bit of hope. Saturday the 1st of August has a 10ft swell from the SSE, but the wind is light and cross-on, so it’s a bit lumpy. The energy is very strong (3008), but it’s a big, messy wave. That’s for experts only. Sunday the 2nd drops to 4ft, but the wind is onshore again.
The one to watch is Wednesday morning, the 5th of August. We’ve got a 3ft swell from the ESE, a 9-second period, and light cross-offshore wind from the NE. The combined energy is moderate (234) and the conditions are clean. It’s not a big wave, but it’s the cleanest option in the second week. It’s a long way off, so don’t hold your breath, but it’s promising.
Overall, the best windows are Wednesday morning the 22nd and Thursday morning the 23rd for clean, small waves. The bigger stuff later on is just messy. Crowds are possible at Onjuku, especially when it’s clean, so get in early.
Stay stoked,
Rusty
Short Range ForecastMostly dry. Warm (max 30°C on Tue morning, min 26°C on Mon night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 8mm), mostly falling on Sat night. Warm (max 27°C on Thu night, min 22°C on Sat night). Wind will be generally light. | ||||||||||||||||||
Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | Sunday 26 | ||||||||||||||
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) | E 11 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | SE 11 | SE 16 | SE 16 | SE 16 | SE 10 | SE 15 | SE 15 | SE 10 |
Wave Graph | |||||||||||||||||||
329 | 257 | 247 | 196 | 196 | 156 | 121 | 113 | 81 | 80 | 57 | 57 | 66 | 65 | 63 | 50 | 55 | 64 | 53 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | glassy | cross-on | cross-on | glassy | glassy | off | cross-off | cross | glassy | cross-off | cross-off | off | cross-off | glassy | cross-off |
High Tide | 9:07AM1.04m | 8:57PM1.32m | 10:41AM0.95m | 9:26PM1.31m | 10:06PM1.28m | 11:05PM1.26m | 4:30PM1.13m | 00:24AM1.25m | 4:42PM1.19m | 1:35AM1.28m | |||||||||
Low Tide | 3:11AM0.58m | 2:24PM0.72m | 4:14AM0.54m | 2:41PM0.85m | 5:28AM0.50m | 6:45AM0.44m | 7:51AM0.37m | 7:16PM1.10m | 8:43AM0.30m | 8:40PM1.07m | |||||||||
— | 4:37 | — | — | 4:39 | — | — | 4:39 | — | — | 4:39 | — | — | 4:41 | — | — | 4:41 | — | — | |
6:51 | — | 6:50 | — | — | 6:50 | — | — | 6:49 | — | — | 6:47 | — | — | 6:47 | — | — | 6:46 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 | — | 4 | 1 | 2 | 3 |
Temp °C | 26 | 30 | 29 | 26 | 29 | 29 | 27 | 29 | 29 | 27 | 27 | 27 | 26 | 26 | 25 | 23 | 25 | 25 | 23 |
Feels °C | 29 | 32 | 30 | 30 | 35 | 32 | 31 | 35 | 34 | 33 | 30 | 31 | 31 | 29 | 27 | 24 | 29 | 30 | 26 |
Swell 1 Height (m) Direction Period (s) | E 11 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | E 9 | E 8 | E 8 | E 8 | E 5 | E 6 | E 6 | E 6 |
329 | 257 | 247 | 196 | 196 | 156 | 121 | 113 | 81 | 80 | 57 | 56 | 51 | 50 | 50 | 22 | 41 | 31 | 16 | |
Swell 2 Height (m) Direction Period (s) | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSW 5 | SSE 7 | SSE 10 | SSW 5 | SSW 5 | SE 10 | SE 9 | SE 11 | SE 10 | SE 10 | SE 10 | SE 10 | SE 11 | SE 10 | SE 10 |
13 | 13 | 12 | 6 | 13 | 5 | 10 | 9 | 8 | 24 | 22 | 57 | 51 | 48 | 49 | 50 | 55 | 64 | 53 | |
Swell 3 Height (m) Direction Period (s) | SE 11 | SE 11 | SE 11 | ESE 11 | SSE 8 | SSE 11 | SSE 7 | SE 10 | SE 10 | SSW 5 | SE 18 | SE 17 | SE 16 | SE 16 | SE 16 | E 8 | SE 15 | SE 15 | S 10 |
5 | 20 | 19 | 12 | 6 | 12 | 5 | 25 | 25 | 5 | 49 | 43 | 66 | 65 | 63 | 21 | 55 | 54 | 48 | |
Wind waves Height (m) Direction Period (s) | SSW 4 | SW 4 | SSW 4 | SSW 4 | SW 5 | SSW 4 | SSW 5 | — | — | NE 2 | NE 4 | ENE 4 | E 3 | SE 3 | SE 3 | — | — | SW 4 | SSW 4 |
5 | 3 | 13 | 10 | 24 | 16 | 12 | — | — | 1 | 4 | 2 | 4 | 2 | 3 | — | — | 3 | 9 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 18 | 9 | 1475 | 9 | 0 | 17 | 17 | 0 | 0 | 0 | 0 | 583 | 0 | 0 | 103 | 0 | 0 | 0 | 0 |
Best forecast wave conditions in Chiba | |||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||
Header Global | |||||||||||||||||||
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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.










