
Surf Forecasts:
Sosanji Rivermouth surf forecast from 7 Aug 2026:
- Best quality surf: Tuesday 11 Aug, 6AM (local time) - 3.5ft (1.1m), 12s period, E swell with glassy winds.
- Most powerful swell: Friday 7 Aug, 9PM (local time) - 10ft (3.0m), 12s period, SSE swell with 2,587 kJ wave energy.
- Next surfable swell (1★+): Tuesday 11 Aug, 6AM (local time) - 3.5ft (1.1m), 12s period with E swell.
Best Forecast Surf Conditions for Sosanji Rivermouth this week:
The surf forecast for Sosanji Rivermouth over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Aug 11) at 6AM. The primary swell is predicted to be 1.1m and 12s period with a secondary swell of 0.8m and 10s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Sosanji Rivermouth in the next 16 days are 3.0m 12s and forecast to arrive on Friday (Aug 07) at 9PM. Winds are predicted to be onshore at the time the swell arrives.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6AM (Tue 11th Aug) | 3.5ft (1.1m) 12s |
| Best Surf | 6AM (Tue 11th Aug) | 3.5ft (1.1m) 12s |
| Most Powerful | 9PM (Fri 7th Aug) | 10ft (3.0m) 12s |
Table - best surf conditions forecast for Sosanji Rivermouth over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let's get stuck into what's on the menu at Sosanji Rivermouth over the next couple of weeks.
Alright, I'll be straight with you – the outlook for Sosanji Rivermouth is a bit of a mixed bag, with a rough start. The next few days are looking pretty average thanks to some stormy conditions and strong, onshore winds. The water temp is sitting at 84°, which is pretty normal for this time of year, so don't fret about that.
We kick off Friday, August 7th with a risk of thunderstorms and strong onshore winds from the East at 25 mph. We're looking at a messy 12 ft SE swell, but the period is a solid 13 seconds. The combined energy is huge (7127), but with those winds, it's just a washing machine. Not one for the paddle out.
Saturday and Sunday the 8th and 9th remain in the same vein – stormy, onshore winds (22 mph on Saturday, dropping to 12-16 mph on Sunday), and a dropping swell from 10 ft down to 8 ft, but still with poor surf conditions. The energy is still moderate to strong (2539 down to 994). This is more of a kite-surfing setup than anything else, to be honest.
Monday the 10th sees the swell drop right down to 5 ft, with the wind easing too, but it’s still onshore from the ESE at 3 mph. It's a marginal forecast, with the energy still moderate at 1295.
Now, there’s a glimmer of hope on Tuesday morning the 11th. We'll see a small 4 ft swell from the East with a nice 12-second period. The wind goes glassy from the NNE at 3 mph, and the forecast says "expect very good surf conditions". The combined energy is moderate (577). This is your best chance for a clean, fun session, but keep your expectations realistic on the size.
Wednesday morning the 12th stays clean with glassy conditions and a 3 ft East swell, but the energy is dropping (344). It’s rideable, but small. The afternoon kicks up a cross-shore wind, ruining it.
From Thursday the 13th through to the middle of the following week, we're in a bit of a lull. Swells are consistently under 3 ft, periods are short to average, and the wind is mostly cross-on or from the East. The energy readings are low, mostly in the 200-400 range. It's going to be a flat spell for a few days.
However, we've got a notable jump on Wednesday, August 19th. The swell comes back with a bang – 10 ft from the East with a 9-second period. The wind is light onshore, but the catch is the combined energy is strong again (1378). The guidance here is pretty clear: this is too big for this break unless you’re a solid expert, and even then, it’s going to be a handful.
We then see a slow drop through the rest of the week, with the swell holding at 7 ft on Thursday the 20th and then fading down to 3 ft by Saturday the 22nd. Winds stay light, so if you're a really experienced surfer, that Thursday morning might be the one to check.
So, for the standouts? Honestly, the only real window for a fun, clean paddle is Tuesday morning, August 11th. It's small, but glassy, and the swell has some decent period. The big swell on the 19th is more of a spectacle for the brave or for tow-in crew.
Keep your eyes on the forecasts for that second week, but for now, don't hold your breath.
Rusty.
Short Range ForecastHeavy rain (total 78mm), heaviest during Sun night. Warm (max 28°C on Fri afternoon, min 26°C on Sun night). Winds decreasing (strong winds from the E on Fri afternoon, light winds from the ESE by Mon morning). | Days 5-7 Weather SummaryLight rain (total 8mm), mostly falling on Wed night. Warm (max 29°C on Wed afternoon, min 25°C on Wed night). Wind will be generally light. | |||||||||||||||||||
Fri 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | ||||||||||||||
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) | SE 13 | SSE 12 | ESE 9 | ESE 9 | ESE 9 | ESE 8 | ESE 8 | ESE 14 | ESE 13 | E 12 | E 12 | E 12 | E 12 | S 11 | SSE 10 | E 12 | SSE 10 | SSE 9 | S 9 | S 9 |
Wave Graph | ||||||||||||||||||||
4401 | 2204 | 1660 | 1528 | 1003 | 688 | 604 | 1419 | 915 | 513 | 480 | 330 | 314 | 229 | 174 | 174 | 125 | 110 | 79 | 79 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | on | on | on | on | on | on | on | on | glassy | cross-on | off | glassy | cross | glassy | cross-on | on | cross |
High Tide | 00:24AM1.79m | 4:09PM1.71m | 1:55AM1.79m | 4:58PM1.85m | 3:13AM1.86m | 5:33PM1.97m | 4:12AM1.96m | 6:03PM2.06m | 5:01AM2.07m | 6:31PM2.13m | 5:44AM2.15m | 6:57PM2.16m | ||||||||
Low Tide | 6:41PM1.44m | 8:23AM0.61m | 8:51PM1.47m | 9:33AM0.47m | 10:08PM1.38m | 10:25AM0.34m | 10:56PM1.27m | 11:09AM0.24m | 11:33PM1.13m | 11:47AM0.18m | 00:07AM1.00m | 12:23PM0.17m | 00:39AM0.87m | |||||||
— | — | 5:33 | — | — | 5:33 | — | — | 5:35 | — | — | 5:35 | — | — | 5:35 | — | — | 5:37 | — | — | |
7:06 | — | — | 7:05 | — | — | 7:04 | — | — | 7:02 | — | — | 7:01 | — | — | 7:00 | — | — | 7:00 | — | |
mm | 4 | 14 | 5 | 4 | 13 | 5 | 7 | 20 | 6 | — | — | — | — | — | — | 1 | 6 | 1 | 1 | 5 |
Temp °C | 28 | 27 | 27 | 28 | 27 | 28 | 28 | 27 | 27 | 28 | 27 | 28 | 28 | 26 | 28 | 29 | 27 | 28 | 28 | 26 |
Feels °C | 27 | 27 | 27 | 28 | 27 | 29 | 30 | 29 | 31 | 32 | 31 | 32 | 32 | 30 | 32 | 30 | 30 | 30 | 31 | 30 |
Swell 1 Height (m) Direction Period (s) | SE 13 | SSE 12 | SSE 11 | S 11 | S 11 | S 11 | ESE 8 | ESE 14 | ESE 13 | E 12 | E 12 | E 12 | E 12 | S 11 | SSE 10 | SSE 10 | SSE 10 | SSE 9 | S 9 | S 9 |
4401 | 2171 | 858 | 403 | 235 | 191 | 604 | 1419 | 915 | 513 | 480 | 330 | 314 | 229 | 170 | 167 | 125 | 110 | 79 | 79 | |
Swell 2 Height (m) Direction Period (s) | — | E 15 | ENE 15 | E 15 | E 15 | E 14 | S 11 | S 11 | S 10 | SE 7 | SSE 11 | S 11 | S 11 | E 11 | E 10 | E 12 | E 10 | E 10 | E 10 | E 10 |
— | 17 | 21 | 17 | 39 | 106 | 235 | 275 | 250 | 112 | 153 | 229 | 229 | 196 | 174 | 174 | 75 | 51 | 48 | 71 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | E 16 | SE 16 | SE 16 | E 14 | S 15 | S 14 | S 10 | SSE 7 | ESE 13 | SE 13 | ESE 13 | NE 5 | NE 4 | SE 12 | SE 12 | SE 12 | ESE 4 |
— | — | — | 5 | 10 | 9 | 306 | 67 | 60 | 130 | 54 | 18 | 7 | 17 | 6 | 1 | 6 | 6 | 6 | 11 | |
Wind waves Height (m) Direction Period (s) | E 11 | ESE 10 | ESE 9 | ESE 9 | ESE 9 | ESE 8 | — | ESE 7 | ESE 6 | — | — | — | — | — | — | S 3 | — | — | ESE 3 | NE 4 |
2726 | 2204 | 1660 | 1528 | 1003 | 688 | — | 214 | 70 | — | — | — | — | — | — | 1 | — | — | 3 | 9 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 791 | 358 | 297 | 297 | 199 | 199 | 358 | 199 | 199 | 199 | 37 | 0 | 21 | 0 | 0 | 116 | 0 | 51 | 51 | 22 |
Best forecast wave conditions in Kyu Shu | ||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||
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Information about the Sosanji Rivermouth Surf forecast
The above surf forecast table for Sosanji Rivermouth provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Sosanji Rivermouth can be found by selecting the local surf guide option on the grey menu. Our Sosanji Rivermouth 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 (Sosanji Rivermouth) 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 Sosanji Rivermouth 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.
Sosanji Rivermouth is 12 km (7 miles) from Miyazaki-shi. If you plan a holiday in Kyu Shu, look for hotels and other accommodation in Miyazaki-shi. Miyazaki-shi has rooms for a wide range of budgets as well as car hire and transport links.











