Surf Forecasts:
Onjuku surf forecast from 16 Jul 2026:
- Best quality surf: Thursday 23 Jul, 12AM (local time) - 3ft (0.9m), 10s period, E swell with cross-offshore winds.
- Most powerful swell: Tuesday 21 Jul, 6AM (local time) - 4.5ft (1.3m), 11s period, E swell with 394 kJ wave energy.
- Next surfable swell (1★+): Thursday 23 Jul, 12AM (local time) - 3ft (0.9m), 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 12AM. The primary swell is predicted to be 0.9m and 10s period with a secondary swell of 0.4m and 4s. 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 1.3m 11s and forecast to arrive on Tuesday (Jul 21) at 6AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 3s period and expected on Wednesday (Jul 22) at 3PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Thu 23rd Jul) | 3ft (0.9m) 10s |
| Best Surf | 12AM (Thu 23rd Jul) | 3ft (0.9m) 10s |
| Most Powerful | 6AM (Tue 21st Jul) | 4.5ft (1.3m) 11s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
The Lowdown
Alright, this is Rusty. Let's have a look at what's on the cards for Onjuku over the next couple of weeks.
Alright, it's a bit of a slow start for Onjuku. The forecast shows a lot of sessions with poor surf conditions and scores that are just not worth paddling out for. The first few days are a write-off, basically. We're looking at Thursday the 23rd before there's anything you'd even call surfable. Early on the 23rd, there's a light cross-offshore breeze, so it'll be clean, but the swell is only 3ft from the east, with a combined energy of 195 (moderate). It's not going to be anything special, but at least you won't be fighting the wind. The real highlight is the glassy session on the 23rd afternoon, with the wind dropping to glass. The swell is still small at 3ft, but if you're desperate for a fun little slide, that's your window.
The real standout is that big bump coming in on Sunday the 26th, and it gets even better on Monday the 27th. On Sunday morning, the swell jumps to 6ft from the SSE (14 seconds), with a combined energy of 1222 (strong), and the wind is a clean cross-offshore from the NE. That's a solid, long-period groundswell, so it'll have some real punch, but it might be a bit straight for the beach break. Still, it's going to be the best looking surf we've seen. Monday the 27th morning is the absolute pick of the forecast. The swell is 7ft from the SSE (13 seconds), combined energy of 1383 (strong), the wind is a light cross-offshore from the ENE, and the conditions are clean. That's excellent for experienced surfers. It's a lot of juice, so leave the foamies at home.
After that, the swell just pumps up too much. Tuesday the 28th and Wednesday the 29th see the swell going over 8ft, and the forecast is saying it's going to be too big for the break. The combined energy on Tuesday the 28th afternoon hits 10983 (very strong), and on Wednesday the 29th morning it's 9998 (very strong). That's a full-on, massive swell. For a beach break like Onjuku, that's going to be a washing machine. It's really only going to be interesting for the experts, or maybe the kite surfers.
The last few days of July and into August see the swell drop back down, but the wind turns onshore or cross-onshore, and the forecasts are all poor. The 1st of August has a 6ft swell from the ENE, but with a moderate cross-onshore wind, it's just going to be a mess.
So, to wrap it up: there's a rough start, a small window for a clean but tiny wave on the 23rd, then the real deal is the standouts on Sunday the 26th and Monday the 27th. After that, it's big and unruly, and then it's gone. The water temperature is about average for the time of year, nothing weird going on there.
Rusty.
Short Range ForecastLight rain (total 3mm), mostly falling on Thu night. Warm (max 27°C on Thu night, min 25°C on Fri night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 4mm), mostly falling on Wed morning. Warm (max 29°C on Wed morning, min 24°C on Sun night). Wind will be generally light. | ||||||||||||||||||
Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | ||||||||||||||
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) | ESE 8 | E 8 | E 8 | ESE 8 | E 8 | ESE 9 | E 9 | ESE 9 | ESE 9 | E 9 | E 8 | E 9 | E 10 | E 11 | E 11 | E 10 | E 10 | E 10 | E 10 |
Wave Graph  | |||||||||||||||||||
 kJ | 118 | 92 | 90 | 122 | 92 | 135 | 180 | 211 | 248 | 194 | 143 | 150 | 277 | 387 | 372 | 242 | 196 | 159 | 153 |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | cross-on | on | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-off |
High Tide | 5:24AM1.49m | 7:20PM1.34m | 6:15AM1.41m | 7:45PM1.33m | 7:06AM1.30m | 8:08PM1.33m | 8:01AM1.17m | 8:32PM1.33m | 9:07AM1.04m | 8:57PM1.32m | 10:41AM0.95m | 9:26PM1.31m | |||||||
Low Tide | 11:55PM0.87m | 12:29PM0.08m | 00:40AM0.77m | 1:04PM0.23m | 1:26AM0.69m | 1:34PM0.40m | 2:16AM0.63m | 2:01PM0.57m | 3:11AM0.58m | 2:24PM0.72m | 4:14AM0.54m | 2:41PM0.85m | |||||||
 |  |  |  | | | | | |  | |  | | | | |  | | | |
 | — | 4:35 | — | — | 4:35 | — | — | 4:37 | — | — | 4:37 | — | — | 4:37 | — | — | 4:39 | — | — |
 | 6:52 | — | 6:52 | — | — | 6:52 | — | — | 6:51 | — | — | 6:51 | — | — | 6:50 | — | — | 6:50 | — |
mm | 1 | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 2 | 2 | 2 |
Temp °C | 27 | 27 | 27 | 25 | 27 | 27 | 25 | 27 | 26 | 25 | 27 | 27 | 25 | 28 | 28 | 26 | 29 | 29 | 27 |
Feels °C | 31 | 30 | 29 | 27 | 29 | 29 | 28 | 29 | 28 | 28 | 29 | 28 | 28 | 31 | 29 | 28 | 33 | 32 | 32 |
Swell 1 Height (m) Direction Period (s) | ESE 8 | E 8 | E 8 | ESE 8 | E 8 | ESE 9 | E 9 | ESE 9 | ESE 9 | E 9 | E 8 | E 9 | E 10 | E 11 | E 11 | E 10 | E 10 | E 10 | E 10 |
| kJ | 118 | 92 | 90 | 122 | 92 | 135 | 180 | 211 | 248 | 194 | 143 | 150 | 277 | 387 | 372 | 242 | 196 | 159 | 153 |
Swell 2 Height (m) Direction Period (s) | S 4 | SE 10 | SE 9 | SE 8 | SSE 9 | SSE 8 | SE 7 | S 8 | S 8 | S 8 | SSE 9 | E 11 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSW 4 | SSW 5 | ENE 4 |
| kJ | 14 | 23 | 22 | 25 | 54 | 27 | 14 | 10 | 5 | 5 | 16 | 58 | 13 | 12 | 12 | 11 | 8 | 5 | 5 |
Swell 3 Height (m) Direction Period (s) | SE 10 | SSW 8 | SSW 8 | SW 7 | SW 7 | SSW 7 | S 8 | SE 12 | SE 12 | S 9 | S 7 | SSE 8 | E 15 | SE 11 | ESE 11 | ESE 11 | SSE 8 | SSE 8 | SSW 4 |
| kJ | 15 | 6 | 6 | 2 | 2 | 5 | 5 | 6 | 6 | 2 | 4 | 13 | 17 | 20 | 12 | 11 | 6 | 6 | 4 |
Wind waves Height (m) Direction Period (s) | S 5 | SSE 4 | SE 4 | S 4 | SE 7 | — | — | — | — | — | — | SSW 3 | SSW 3 | SSW 4 | SSW 4 | SSW 4 | — | NE 3 | ENE 4 |
| kJ | 28 | 25 | 22 | 8 | 11 | — | — | — | — | — | — | 2 | 4 | 5 | 16 | 9 | — | 5 | 6 |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 9 | 9 | 598 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 17 | 9 | 17 | 9 | 17 | 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.
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