
Surf Forecasts:
Onjuku surf forecast from 18 Jul 2026:
- Best quality surf: Wednesday 22 Jul, 9AM (local time) - 3ft (0.9m), 10s period, E swell with glassy winds.
- Most powerful swell: Monday 20 Jul, 9PM (local time) - 4ft (1.2m), 11s period, E swell with 335 kJ wave energy.
- Next surfable swell (1★+): Wednesday 22 Jul, 9AM (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 Wednesday (Jul 22) at 9AM. The primary swell is predicted to be 0.9m and 10s period with a secondary swell of 0.4m and 4s. Another secondary swell of 0.6m and 4s 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 Monday (Jul 20) at 9PM. 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 4s period and expected on Friday (Jul 24) at 12PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Wed 22nd Jul) | 3ft (0.9m) 10s |
| Best Surf | 9AM (Wed 22nd Jul) | 3ft (0.9m) 10s |
| Most Powerful | 9PM (Mon 20th Jul) | 4ft (1.2m) 11s |
Table - best surf conditions forecast for Onjuku over the next 16 days.
The Lowdown
Alright, grab a seat and let’s have a look at what’s cookin' for Onjuku over the next couple of weeks. I’m Rusty, and I’ll be straight with you—it’s a mixed bag, and you’ve gotta be patient.
First up, the water temp is sitting right around 78°, which is pretty much normal for this time of year. No complaints there.
So, for the next several days, honestly, it’s a bit of a write-off. From Sunday the 19th right through to the end of July, the conditions are just not cooperating. The wind is mostly onshore or cross-onshore, chopping up what little swell is around. The waves are small, mostly under 4 ft, and the energy is weak to moderate at best. You’ll see some glassy conditions on the morning of Wednesday the 22nd, with 3 ft of swell from the east, but it’s just ordinary surf. Not worth paddling out for unless you’re desperate for a float.
There’s a real gap here. From the 19th through to the 31st, there’s nothing that gets the heart racing. The swell tries to pick up around the 28th and 29th, with solid 5 ft to 8 ft south swells, and even a long-period groundswell of 15 seconds, but the wind is cross-onshore or onshore, ruining the quality. The wave energy gets strong (839 to 2259) but it’s messy and choppy. That’s more of a kite-surfing setup than a clean paddle session.
As we roll into the first week of August, things start to look a bit more promising. On the morning of Sunday the 2nd, the swell drops back to 4 ft from the southeast, with a very long period of 16 seconds, but the wind is onshore. Still, the energy is solid (1551). It’s marginal, but there’s a hint of something better.
Now, here’s the standout. If you can hold out until Monday the 3rd of August, you’re in for a treat. The morning brings a solid 8 ft southeast swell, with a very long period of 18 seconds. The wind is light and offshore from the east-northeast, and the conditions are clean. The combined wave energy is pumping at 3926—strong stuff. This is an excellent setup for experienced surfers, because at 8 ft, it’s too big for beginners. The long period means the waves will have plenty of power and shape, but at a beach break like Onjuku, that long period can make them break a bit too straight. Still, for the crew that knows what they’re doing, this is the best on offer in the whole forecast. The afternoon holds up well too, with similar size and clean conditions, though the wind picks up a notch.
All in all, it’s a long wait. The first week is a washout, and then there’s a proper window of promising surf on the 3rd of August. Keep an eye on it, because long-range calls can shift, but right now, that Monday morning is the one to pencil in.
Rusty, signing off.
Short Range ForecastMostly dry. Warm (max 29°C on Mon afternoon, min 26°C on Sun night). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 19mm), heaviest on Fri night. Warm (max 29°C on Wed morning, min 22°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Sunday 19 | Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | |||||||||||||||
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) | ESE 9 | E 9 | E 9 | E 9 | E 8 | E 11 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | SE 11 | SE 16 | SE 16 | SE 16 | SE 15 |
Wave Graph | |||||||||||||||||||||
232 | 165 | 127 | 119 | 116 | 329 | 305 | 247 | 192 | 156 | 153 | 143 | 113 | 116 | 80 | 57 | 57 | 66 | 65 | 63 | 63 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | glassy | cross-on | cross-on | cross-off | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off |
High Tide | 8:08PM1.33m | 8:01AM1.17m | 8:32PM1.33m | 9:07AM1.04m | 8:57PM1.32m | 10:41AM0.95m | 9:26PM1.31m | 10:06PM1.28m | 11:05PM1.26m | 4:30PM1.13m | 00:24AM1.25m | ||||||||||
Low Tide | 1:34PM0.40m | 2:16AM0.63m | 2:01PM0.57m | 3:11AM0.58m | 2:24PM0.72m | 4:14AM0.54m | 2:41PM0.85m | 5:28AM0.50m | 6:45AM0.44m | 7:51AM0.37m | 7:16PM1.10m | ||||||||||
4:37 | — | — | 4:37 | — | — | 4:37 | — | — | 4:39 | — | — | 4:39 | — | — | 4:39 | — | — | 4:41 | — | — | |
— | 6:51 | — | — | 6:51 | — | — | 6:50 | — | — | 6:50 | — | — | 6:49 | — | — | 6:47 | — | — | 6:47 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 7 | — | — | 12 | — | 1 | 1 |
Temp °C | 27 | 27 | 26 | 28 | 29 | 26 | 29 | 29 | 27 | 29 | 29 | 27 | 29 | 29 | 27 | 26 | 25 | 23 | 25 | 25 | 23 |
Feels °C | 29 | 29 | 29 | 31 | 31 | 28 | 32 | 31 | 31 | 35 | 33 | 31 | 34 | 34 | 32 | 27 | 25 | 24 | 25 | 25 | 24 |
Swell 1 Height (m) Direction Period (s) | ESE 9 | E 9 | E 9 | E 9 | E 8 | E 11 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 10 | E 9 | E 9 | E 9 | E 8 | E 8 | ENE 8 | SE 10 |
232 | 165 | 127 | 119 | 116 | 329 | 305 | 247 | 192 | 156 | 153 | 143 | 113 | 116 | 80 | 57 | 56 | 35 | 35 | 53 | 63 | |
Swell 2 Height (m) Direction Period (s) | S 8 | S 8 | SSE 7 | S 7 | E 14 | SSE 8 | SSW 4 | SSE 8 | SSE 8 | SSW 4 | SSW 4 | SSW 4 | SE 10 | SSW 5 | SE 10 | SE 9 | SE 11 | SE 10 | SE 10 | SE 10 | ENE 6 |
10 | 11 | 29 | 25 | 60 | 13 | 7 | 12 | 6 | 6 | 6 | 4 | 25 | 6 | 24 | 22 | 57 | 54 | 48 | 49 | 15 | |
Swell 3 Height (m) Direction Period (s) | SE 12 | SE 12 | S 8 | S 7 | SSE 7 | SE 11 | SSE 8 | SE 11 | ESE 11 | SSE 8 | SSE 7 | SSE 10 | SSW 5 | SE 10 | SE 18 | SE 18 | SE 17 | SE 16 | SE 16 | SE 16 | SE 15 |
6 | 6 | 10 | 4 | 4 | 5 | 13 | 19 | 12 | 6 | 5 | 10 | 4 | 25 | 49 | 49 | 43 | 66 | 65 | 63 | 57 | |
Wind waves Height (m) Direction Period (s) | SSE 8 | SSE 4 | — | — | SSW 4 | SW 4 | SW 4 | SSW 4 | SSW 4 | SW 4 | SSW 4 | SW 5 | — | — | — | NE 3 | NE 4 | NE 4 | NE 4 | — | — |
54 | 13 | — | — | 10 | 7 | 11 | 15 | 6 | 16 | 13 | 11 | — | — | — | 4 | 6 | 7 | 6 | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 9 | 9 | 9 | 9 | 17 | 17 | 9 | 17 | 9 | 0 | 9 | 2 | 0 | 205 | 16 | 56 | 240 | 16 | 56 | 56 | 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.










