
Surf Forecasts:
Onjuku surf forecast from 21 Jul 2026:
- Best quality surf: Sunday 26 Jul, 3PM (local time) - 3.5ft (1.1m), 6s period, E swell with cross-offshore winds.
- Most powerful swell: Sunday 26 Jul, 9PM (local time) - 5ft (1.6m), 6s period, E swell with 209 kJ wave energy.
- Next surfable swell (1★+): Thursday 23 Jul, 9AM (local time) - 2.5ft (0.7m), 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 Thursday (Jul 23) at 9AM. The primary swell is predicted to be 0.7m and 10s period with a secondary swell of 0.6m and 6s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Onjuku in the next 16 days are 1.6m 6s and forecast to arrive on Sunday (Jul 26) at 9PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 5s period and expected on Saturday (Jul 25) at 6PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Thu 23rd Jul) | 2.5ft (0.7m) 10s |
| Best Surf | 3PM (Sun 26th Jul) | 3.5ft (1.1m) 6s |
| Most Powerful | 9PM (Sun 26th Jul) | 5ft (1.6m) 6s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
The Lowdown
Righto, let’s have a look at what’s cookin’ for Onjuku. This is a bit of a mixed bag, to be honest. The first week or so is pretty flat and average, but there’s a serious pulse of energy building for the start of August that could fire up.
For the first few days, starting Wednesday the 22nd, it’s a bit of a struggle. We’ve got a weak, short-period easterly swell hanging around, mostly around 2ft to 3ft, with a period of 9 to 10 seconds. The wind’s mainly cross-onshore, and the water’s just got that messy, choppy look. The combined swell energy is moderate at best, sitting around 124 to 217 (217). It’s surfable, but you’d be fighting for crummy little waves. Thursday morning the 23rd looks a bit tidier with a light cross-offshore breeze from the NE, making things clean, but the waves are tiny at 2ft. It’s not really worth paddling out for unless you’re desperate for a splash.
We get a bit of a glimmer on Sunday the 26th afternoon. The wind goes glassy, and the swell bumps up to 4ft from the ESE, but the period is a shocking 5 seconds – that’s pure wind chop. The combined energy is 213 (213), so there’s some push, but it’s messy. Still, if you’re there with a foamie, you might snag a few grovelly ones.
Then we hit a bit of a lull. Monday the 27th through to the end of the month are dominated by those pesky SW winds, with swell dropping to 1.0ft to 2ft. The combined energy plummets to as low as 39 (39). It’s a real flat spell. Not much doing.
Now, here’s where it gets interesting. The first couple of days of August look promising, but with a big caveat. On Saturday the 1st, we’ve got a tiny 1ft swell, but the period is a massive 17 seconds from the ESE. That’s a long-period groundswell, and with glassy conditions in the morning, it could be clean, but it’s going to be very weak and inconsistent. The combined energy is 222 (222), which is moderate, but the size is tiny.
Then, hold onto your board, because Sunday the 2nd and Monday the 3rd are the real standouts. Sunday the 2nd morning sees a 4ft ESE swell with a 15-second period, and the combined energy jumps to 1022 (1022) – that’s strong energy. The wind is light onshore, so it’s not perfect, but the size and period are there. The real gem is Monday the 3rd afternoon. We’re looking at a solid 7ft swell from the south, with a 14-second period, and the combined energy is a massive 3023 (3023). The wind is cross-offshore from the ENE, keeping it clean. This is proper, powerful groundswell. 7ft is getting up there, so it’s for experienced surfers only. The long period means it’ll be better on a point or reef, rather than the beach break, but if Onjuku is handling it, those waves will have some serious grunt. The crowd situation is listed as “sometimes” busy, so you might have some company, but it’s worth it.
After that, the wind really cranks up. Tuesday the 4th through to Thursday the 6th still have a big 6ft to 6ft ESE swell, with very long 15-16 second periods, and the combined energy is still strong, between 1672 and 3008 (1672). But the wind is a fresh to strong breeze, 18 to 28 mph. Those conditions will be wild, with massive wind chop and blown-out faces. It’s more of a kite-surfing show than a paddling session at that point.
So, for the best of it, your window is Monday the 3rd of August afternoon. That’s the one. The swell’s big, the period is long, and the wind is off. Don’t be late, and don’t be a beginner.
Rusty.
Short Range ForecastLight rain (total 3mm), mostly falling on Thu night. Warm (max 30°C on Wed morning, min 24°C on Thu night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 21mm), heaviest during Sat night. Warm (max 27°C on Sat morning, min 21°C on Sun night). Wind will be generally light. | ||||||||||||||||||||
Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | Sunday 26 | Monday 27 | Tuesday 28 | |||||||||||||||
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) | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | SE 11 | SE 16 | SE 10 | SE 16 | SE 10 | ENE 7 | E 6 | E 7 | ESE 7 | ESE 7 | NE 8 | NE 8 | ENE 8 | ENE 7 |
Wave Graph | |||||||||||||||||||||
196 | 156 | 121 | 87 | 81 | 58 | 57 | 57 | 73 | 51 | 63 | 50 | 77 | 91 | 168 | 111 | 79 | 99 | 93 | 39 | 43 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | off | off | cross-off | off | cross-off | on | glassy |
High Tide | 10:41AM0.95m | 9:26PM1.31m | 10:06PM1.28m | 11:05PM1.26m | 4:30PM1.13m | 00:24AM1.25m | 4:42PM1.19m | 1:35AM1.28m | 5:00PM1.23m | 2:32AM1.33m | 5:21PM1.27m | ||||||||||
Low Tide | 2:41PM0.85m | 5:28AM0.50m | 6:45AM0.44m | 7:51AM0.37m | 7:16PM1.10m | 8:43AM0.30m | 8:40PM1.07m | 9:26AM0.23m | 9:28PM1.02m | 10:04AM0.17m | 10:04PM0.97m | ||||||||||
4:39 | — | — | 4:39 | — | — | 4:39 | — | — | 4:41 | — | — | 4:41 | — | — | 4:43 | — | — | 4:43 | — | — | |
— | 6:50 | — | — | 6:49 | — | — | 6:47 | — | — | 6:47 | — | — | 6:46 | — | — | 6:45 | — | — | 6:45 | — | |
mm | — | — | — | — | — | 3 | — | — | — | — | — | 8 | 5 | 3 | 5 | — | — | — | — | — | — |
Temp °C | 30 | 29 | 27 | 29 | 29 | 27 | 27 | 27 | 26 | 27 | 26 | 24 | 24 | 24 | 24 | 24 | 25 | 23 | 25 | 26 | 25 |
Feels °C | 31 | 30 | 30 | 34 | 33 | 32 | 30 | 30 | 30 | 29 | 28 | 26 | 26 | 26 | 28 | 25 | 25 | 24 | 28 | 28 | 28 |
Swell 1 Height (m) Direction Period (s) | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | E 9 | E 9 | E 8 | SE 10 | ENE 6 | ENE 7 | SE 10 | E 7 | ESE 7 | ESE 7 | ESE 6 | NE 8 | ENE 8 | ENE 7 |
196 | 156 | 121 | 87 | 81 | 58 | 57 | 39 | 73 | 51 | 49 | 25 | 77 | 65 | 168 | 111 | 79 | 43 | 46 | 39 | 43 | |
Swell 2 Height (m) Direction Period (s) | SSE 8 | SSE 11 | SSE 11 | SSW 6 | SSW 6 | SE 10 | SE 9 | SE 11 | SE 10 | SE 10 | E 8 | SE 10 | SE 10 | SE 15 | SE 10 | SE 10 | SE 10 | NE 7 | E 7 | SE 10 | SE 10 |
6 | 12 | 11 | 28 | 22 | 24 | 22 | 57 | 51 | 48 | 34 | 50 | 54 | 54 | 51 | 49 | 50 | 44 | 32 | 35 | 35 | |
Swell 3 Height (m) Direction Period (s) | — | SSE 7 | SSE 7 | SE 10 | SE 10 | SSW 5 | SE 18 | ENE 4 | SE 16 | SE 4 | SE 16 | E 8 | SE 5 | S 9 | SE 14 | NE 8 | NE 9 | SE 10 | SE 10 | ESE 7 | S 6 |
— | 5 | 5 | 25 | 25 | 5 | 49 | 3 | 66 | 5 | 63 | 21 | 6 | 7 | 72 | 30 | 38 | 50 | 36 | 15 | 17 | |
Wind waves Height (m) Direction Period (s) | SSW 5 | SSW 5 | SSW 5 | — | ENE 2 | ENE 3 | NE 3 | — | SE 4 | SE 4 | ENE 5 | — | SE 5 | E 6 | — | — | — | NE 8 | NE 8 | — | — |
14 | 37 | 23 | — | 1 | 1 | 4 | — | 4 | 3 | 23 | — | 8 | 91 | — | — | — | 99 | 93 | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 17 | 1489 | 17 | 0 | 0 | 0 | 56 | 9 | 9 | 40 | 56 | 15 | 12 | 0 | 0 | 0 | 56 | 0 | 0 | 9 | 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.










