Surf Forecasts:
Onjuku surf forecast from 21 Jul 2026:
- Best quality surf: Thursday 23 Jul, 6AM (local time) - 2.5ft (0.8m), 10s period, E swell with glassy winds.
- Most powerful swell: Wednesday 22 Jul, 12AM (local time) - 3.5ft (1.0m), 10s period, E swell with 196 kJ wave energy.
- Next surfable swell (1★+): Thursday 23 Jul, 6AM (local time) - 2.5ft (0.8m), 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 6AM. The primary swell is predicted to be 0.8m and 10s period with a secondary swell of 0.6m and 6s. Another secondary swell of 1.0m and 6s 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 1.0m 10s and forecast to arrive on Wednesday (Jul 22) 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 0.6m 4s period and expected on Friday (Jul 24) at 3AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6AM (Thu 23rd Jul) | 2.5ft (0.8m) 10s |
| Best Surf | 6AM (Thu 23rd Jul) | 2.5ft (0.8m) 10s |
| Most Powerful | 12AM (Wed 22nd Jul) | 3.5ft (1.0m) 10s |
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 on the menu for the next couple of weeks.
Truth be told, it’s a tough stretch ahead. We’re looking at a long, quiet run with nothing really worth paddling out for until we get deep into the second week. The immediate period is a write-off, with hardly any energy and messy conditions.
The first real glimmer of something happens on the morning of Saturday, 1st August. Onjuku sees a pulse of new swell, 3 ft from the SSE with a decent 12-second period behind it. The combined energy climbs to 586 – that’s moderate energy, but it’s a start. The wind is light from the SE, keeping it just cross-onshore with small ripples. It’s only marginal, but compared to the flat spell before it, it’s the best we’ve seen.
Things get a bit more interesting on Sunday, 2nd August. The swell pushes up to 5 ft from the S, with a very long 14-second period. That’s proper groundswell energy, and the combined energy hits 1263, which is strong. The problem is the wind. It’s a moderate SE breeze, cross-onshore, and with the risk of thunderstorms, it’s going to be choppy and messy. This is decent size for a beach break but the onshore wind will spoil it. This is more of a kite surfing setup than a clean paddle session.
The standout, if you can call it that, looks like the morning of Tuesday, 4th August. The swell holds at 5 ft from the S (14s period), and the combined energy is still strong at 1140. The wind shifts to a light ESE breeze, turning it into a gentle cross-shore with just a slight chop. This is the cleanest we’ll see it, and the best chance for a few grunty ones. The water temp is about 77°, average for the time of year. It’s still not perfect, but it’s the pick of a bare patch.
After that, it fades again into smaller, onshore slop through the 5th. Not a classic run, but that Tuesday morning holds a little promise.
Rusty.
Short Range ForecastLight rain (total 2mm), mostly falling on Thu night. Warm (max 30°C on Tue afternoon, min 25°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryModerate rain (total 19mm), heaviest on Fri night. Warm (max 28°C on Fri afternoon, min 23°C on Fri night). Wind will be generally light. | |||||||||||||||||||
Tue 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | Sunday 26 | Monday 27 | ||||||||||||||
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 10 | E 10 | E 9 | E 9 | E 9 | SE 11 | SE 10 | SE 10 | SE 10 | SE 15 | SE 10 | SE 15 | SE 14 | ESE 10 | SE 10 | SE 10 |
Wave Graph  | ||||||||||||||||||||
 kJ | 247 | 196 | 196 | 156 | 121 | 87 | 81 | 58 | 57 | 57 | 51 | 51 | 49 | 57 | 54 | 64 | 72 | 70 | 80 | 80 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-on | cross | cross-off | cross-off | cross-off | cross | cross-on | cross-on | on | on | cross-on |
High Tide | 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 | 5:00PM1.23m | 2:32AM1.33m | |||||||||
Low Tide | 4:14AM0.54m | 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 | ||||||||||
 |  | | | | | |  |  | |  | | |  | | |  |  | | | |
 | — | — | 4:39 | — | — | 4:39 | — | — | 4:39 | — | — | 4:41 | — | — | 4:41 | — | — | 4:43 | — | — |
 | 6:50 | — | — | 6:50 | — | — | 6:49 | — | — | 6:47 | — | — | 6:47 | — | — | 6:46 | — | — | 6:45 | — |
mm | — | — | — | — | — | — | — | 2 | — | — | 8 | — | — | — | — | — | 4 | 7 | — | 1 |
Temp °C | 30 | 27 | 30 | 29 | 27 | 28 | 29 | 26 | 27 | 28 | 26 | 25 | 24 | 24 | 25 | 26 | 25 | 25 | 26 | 26 |
Feels °C | 31 | 31 | 32 | 31 | 30 | 32 | 32 | 30 | 31 | 32 | 29 | 25 | 24 | 26 | 26 | 28 | 28 | 27 | 28 | 29 |
Swell 1 Height (m) Direction Period (s) | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | E 9 | E 9 | E 8 | E 8 | ENE 8 | E 8 | SE 10 | SE 10 | ESE 10 | SE 10 | SE 10 |
| kJ | 247 | 196 | 196 | 156 | 121 | 87 | 81 | 58 | 57 | 39 | 38 | 51 | 49 | 51 | 46 | 64 | 53 | 65 | 80 | 80 |
Swell 2 Height (m) Direction Period (s) | SSE 8 | SSE 8 | SSW 5 | SSE 11 | SSE 11 | SSW 6 | SSW 6 | SE 10 | SE 9 | SE 11 | ESE 4 | SE 10 | SE 10 | SE 10 | SE 10 | E 8 | ENE 9 | SSE 4 | SE 5 | ENE 7 |
| kJ | 12 | 6 | 15 | 12 | 11 | 25 | 21 | 24 | 22 | 57 | 6 | 48 | 49 | 50 | 54 | 29 | 34 | 12 | 18 | 21 |
Swell 3 Height (m) Direction Period (s) | SE 11 | ESE 11 | SSE 8 | SSE 7 | SE 7 | SE 10 | SE 10 | SSW 5 | SE 18 | SE 17 | SE 10 | SE 4 | SE 4 | SE 15 | SE 4 | SE 15 | SE 14 | SE 14 | S 9 | SE 5 |
| kJ | 19 | 12 | 6 | 5 | 2 | 25 | 25 | 5 | 49 | 43 | 51 | 7 | 7 | 57 | 5 | 54 | 72 | 70 | 24 | 10 |
Wind waves Height (m) Direction Period (s) | SSW 4 | SSW 4 | SW 5 | SSW 5 | SSW 5 | — | NE 3 | NE 3 | ENE 4 | ENE 4 | SE 4 | — | — | SE 4 | — | SSE 4 | SSE 4 | S 4 | NE 3 | ENE 4 |
| kJ | 20 | 11 | 33 | 35 | 20 | — | 2 | 4 | 6 | 5 | 7 | — | — | 6 | — | 7 | 11 | 16 | 3 | 12 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 1475 | 9 | 9 | 1489 | 17 | 0 | 56 | 0 | 0 | 9 | 9 | 56 | 536 | 0 | 56 | 9 | 9 | 9 | 9 | 9 |
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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