
Surf Forecasts:
Onjuku surf forecast from 13 Jul 2026:
- Best quality surf: Sunday 19 Jul, 6PM (local time) - 5ft (1.6m), 9s period, ESE swell with cross-offshore winds.
- Most powerful swell: Monday 20 Jul, 12AM (local time) - 6ft (1.8m), 9s period, ESE swell with 499 kJ wave energy.
- Next surfable swell (1★+): Monday 13 Jul, 9PM (local time) - 3.5ft (1.0m), 12s period with S 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 9PM. The primary swell is predicted to be 1.0m and 12s period with a secondary swell of 0.3m and 9s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Onjuku in the next 16 days are 1.8m 9s and forecast to arrive on Monday (Jul 20) at 12AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 3s period and expected on Saturday (Jul 18) at 9AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Mon 13th Jul) | 3.5ft (1.0m) 12s |
| Best Surf | 6PM (Sun 19th Jul) | 5ft (1.6m) 9s |
| Most Powerful | 12AM (Mon 20th Jul) | 6ft (1.8m) 9s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
Alright folks, Rusty here. Let’s have a look at what Onjuku is cooking up for us.
First up, the water temperature is sitting at 76°, which is about normal for this time of year – nothing crazy there.
The forecast starts off with a bit of a slow burn. Monday the 13th has a morning window with a 4 ft SSW swell, period of 13 seconds, and a cross-offshore wind. The combined energy is moderate at 475, and it’s looking clean. That’s the best we’ve got in the early days, but it’s not a standout. The rest of the week is mostly a write-off with onshore winds, small surf, and messy conditions. There’s a real lull mid-week, with Wednesday the 15th through Friday the 17th offering almost nothing worth paddling out for.
Now, things start to get interesting heading into the weekend of the 18th and 19th. On Saturday the 18th, we’ve got a 4 ft to 4 ft ESE swell with clean conditions thanks to a cross-offshore NE wind. The energy bumps up to 310-332, but it’s still just a marginal call. Sunday the 19th afternoon looks a bit better with a 5 ft ESE swell, again clean, and the energy climbing to 444. It’s getting there, but not quite a standout.
The real highlight, and the one you want to circle, is Wednesday the 22nd. The morning session is where it’s at. We’re looking at a 7 ft E swell with a period of 11 seconds, zero wind – glassy as it gets. The combined energy is a solid 1228, which is strong. This is expert territory at that size, but the conditions are prime. The swell direction from the E is a touch off the optimum SSE, but for a clean, glassy morning with that much power, it’s the pick of the 16 days by a long shot. After that, the swell backs off and the wind turns messy again.
Overall, there’s a long gap of poor surf from the 13th through the 17th, then a slow build to that one standout morning on the 22nd. After that, it’s a mix of marginal and poor conditions through the rest of the window. The 22nd is the one to chase if you’ve got the skill.
Rusty.
Short Range ForecastSome drizzle, heaviest during Mon morning. Warm (max 28°C on Tue morning, min 24°C on Mon night). Winds increasing (calm on Tue morning, fresh winds from the SSW by Wed night). | Days 4-6 Weather SummaryModerate rain (total 10mm), heaviest on Thu night. Warm (max 27°C on Thu morning, min 24°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Monday 13 | Tuesday 14 | Wednesday 15 | Thursday 16 | Friday 17 | Saturday 18 | Sunday 19 | |||||||||||||||
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) | SSW 13 | SSW 12 | SSW 11 | SSW 11 | SSW 10 | S 10 | SSW 10 | E 9 | SSW 6 | S 6 | E 8 | E 8 | E 9 | E 9 | E 8 | SE 10 | ESE 9 | E 8 | SE 10 | ESE 9 | ESE 9 |
Wave Graph | |||||||||||||||||||||
424 | 167 | 213 | 123 | 86 | 51 | 31 | 39 | 122 | 77 | 66 | 71 | 99 | 94 | 90 | 261 | 295 | 195 | 216 | 311 | 499 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-on | cross-off | glassy | on | cross-on | cross-on | on | cross-on | cross-on | on | on | on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 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 | 7:45PM1.33m | 7:06AM1.30m | 8:08PM1.33m | ||||||||
Low Tide | 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 | 1:26AM0.69m | 1:34PM0.40m | 2:16AM0.63m | |||||||
4:33 | — | — | 4:33 | — | — | 4:33 | — | — | 4:35 | — | — | 4:35 | — | — | 4:35 | — | — | 4:37 | — | — | |
— | 6:53 | — | — | 6:53 | — | — | 6:52 | — | — | 6:52 | — | — | 6:52 | — | — | 6:52 | — | — | 6:51 | — | |
mm | 1 | — | — | — | — | — | — | — | — | — | — | 8 | 2 | — | — | — | — | — | — | 1 | — |
Temp °C | 26 | 27 | 26 | 28 | 28 | 26 | 28 | 27 | 26 | 27 | 27 | 26 | 27 | 27 | 25 | 26 | 26 | 24 | 25 | 26 | 25 |
Feels °C | 30 | 31 | 29 | 31 | 30 | 28 | 30 | 28 | 26 | 29 | 29 | 29 | 30 | 29 | 28 | 26 | 27 | 25 | 27 | 29 | 28 |
Swell 1 Height (m) Direction Period (s) | SSW 13 | S 7 | SSW 11 | SSW 11 | SSW 10 | S 10 | ESE 9 | E 9 | E 9 | E 8 | E 8 | E 8 | E 9 | E 9 | E 8 | SE 10 | ESE 9 | E 8 | E 8 | ESE 9 | ESE 9 |
424 | 73 | 213 | 123 | 86 | 51 | 26 | 39 | 76 | 66 | 66 | 71 | 99 | 94 | 90 | 261 | 295 | 195 | 185 | 311 | 499 | |
Swell 2 Height (m) Direction Period (s) | ESE 9 | SSW 12 | ESE 9 | ESE 9 | SE 10 | ESE 9 | SSW 10 | SSE 11 | SSE 11 | SSE 9 | SE 10 | SE 10 | SE 10 | SE 9 | SE 9 | E 8 | SSW 9 | SE 9 | SE 10 | SE 11 | SE 12 |
27 | 167 | 16 | 15 | 35 | 28 | 31 | 12 | 11 | 8 | 16 | 25 | 23 | 22 | 28 | 66 | 8 | 120 | 216 | 133 | 54 | |
Swell 3 Height (m) Direction Period (s) | SE 10 | ESE 9 | SSE 10 | SE 12 | E 10 | SE 10 | SE 10 | SSE 9 | SSE 9 | SSW 9 | SSW 8 | SSW 8 | SSW 8 | SSW 8 | SE 13 | SSW 7 | SW 7 | S 9 | S 11 | W 6 | S 9 |
24 | 16 | 9 | 22 | 9 | 26 | 25 | 8 | 8 | 7 | 7 | 6 | 6 | 6 | 61 | 5 | 7 | 14 | 57 | 1 | 41 | |
Wind waves Height (m) Direction Period (s) | — | — | — | NE 3 | — | S 3 | SSW 3 | SSW 4 | SSW 6 | S 6 | S 5 | SSE 5 | SSE 5 | SSE 4 | SSE 4 | ENE 3 | — | — | — | — | — |
— | — | — | 2 | — | 1 | 3 | 28 | 122 | 77 | 54 | 31 | 33 | 23 | 10 | 4 | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 2 | 0 | 0 | 9 | 17 | 143 | 9 | 536 | 17 | 9 | 9 | 9 | 9 | 0 | 51 | 51 | 51 | 40 | 0 | 0 |
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.










