
Surf Forecasts:
Monabe Rivermouth surf forecast from 15 Jul 2026:
- Most powerful swell: Tuesday 21 Jul, 3AM (local time) - 2ft (0.6m), 11s period, E swell with 82 kJ wave energy.
Best Forecast Surf Conditions for Monabe Rivermouth this week:
The most powerful waves expected at Monabe Rivermouth in the next 16 days are 0.6m 11s and forecast to arrive on Tuesday (Jul 21) at 3AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 8s period and expected on Thursday (Jul 16) at 3AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 3AM (Tue 21st Jul) | 2ft (0.6m) 11s |
Table - best surf conditions forecast for Monabe Rivermouth over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s on offer for Monabe Rivermouth over the next couple of weeks.
Straight up, there’s a long, quiet stretch ahead. For the first week and a half, we’re looking at a real flat spell. From Wednesday the 15th of July all the way through to the 24th, there’s nothing doing. The swell is tiny—around 1ft to 2ft—and the combined energy is weak, barely cracking 100 (42 to 104). It’s a river break that *rarely breaks* anyway, so this blank run is pretty normal for the area. Water temps are sitting at 81°, which is about average for the time of year, so no surprises there.
The wait drags on until the 24th of July, Friday afternoon, when a bit of a jump happens. The swell suddenly bumps up to 3ft from the SW with a short period of 6 seconds, and the energy climbs to 180. But it’s a messy, poor-quality onshore situation—not worth getting excited about.
The first real sign of life comes on the morning of Saturday the 25th of July. It’s still tiny at 1ft, but we’ve got a *very long period* groundswell from the SE at 16 seconds, and the energy is up to 225. The wind is glassy, so the surface is clean. However, the forecast says *surfable waves but very ordinary conditions*. This break is a rivermouth, so with that super long period, the waves might be fat and straight, but if you’re desperate for a knee-high glide, that’s your window.
The real standout, and the only one worth marking on the calendar, is the morning of Thursday the 30th of July. Now we’re talking. The swell pushes up to 6ft from the SE, with a period of 16 seconds. That’s a very long period groundswell, and the combined energy is a solid 1762—strong wave energy. The wind is glassy, which means clean, peeling lines. For a rivermouth, that long period could mean the waves set up nicely, but be aware it might break a little straight. Still, this is the best on offer by a long shot. The conditions are described as *expect good surf conditions*.
But a word of caution: this spot is *rarely breaks*, and when it does, crowds are *sometimes* a factor. For a morning like that, you might have some company. Also, 6ft is on the edge for beginners—it’s better suited to intermediate and above.
So, if you’re patient, aim for the 30th of July morning. The rest of the 16-day window is a waiting game.
Rusty.
Short Range ForecastMostly dry. Warm (max 30°C on Wed afternoon, min 26°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Sat night. Warm (max 30°C on Sat afternoon, min 26°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Wed 15 | Thursday 16 | Friday 17 | Saturday 18 | Sunday 19 | Monday 20 | Tuesday 21 | |||||||||||||||
PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | |
Swell Height Map | |||||||||||||||||||||
Wave Height (m) Direction Period (s) | SE 10 | ESE 9 | ESE 10 | ESE 10 | E 10 | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | E 9 | E 9 | E 9 | E 9 | E 10 | E 10 | E 9 | ESE 10 | E 11 | E 12 |
Wave Graph | |||||||||||||||||||||
27 | 17 | 30 | 31 | 29 | 27 | 25 | 41 | 39 | 48 | 42 | 43 | 44 | 59 | 60 | 64 | 70 | 40 | 36 | 57 | 69 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | glassy | glassy | cross-on | off | glassy | on | glassy | glassy | on | glassy | glassy | on | glassy | glassy | on | glassy | glassy | on | off | glassy |
High Tide | 7:28PM1.86m | 6:33AM1.89m | 8:05PM1.84m | 7:20AM1.86m | 8:40PM1.80m | 8:08AM1.78m | 9:12PM1.74m | 8:56AM1.65m | 9:43PM1.69m | 9:48AM1.51m | 10:14PM1.63m | 10:51AM1.37m | 10:46PM1.56m | ||||||||
Low Tide | 00:58AM0.86m | 1:21PM-0.05m | 1:40AM0.79m | 2:01PM0.07m | 2:22AM0.74m | 2:40PM0.24m | 3:06AM0.70m | 3:16PM0.45m | 3:52AM0.67m | 3:50PM0.66m | 4:44AM0.67m | 4:25PM0.85m | 5:45AM0.66m | ||||||||
— | — | 5:05 | — | — | 5:05 | — | — | 5:07 | — | — | 5:07 | — | — | 5:07 | — | — | 5:09 | — | — | 5:09 | |
7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:14 | — | — | 7:14 | — | — | 7:13 | — | — | 7:13 | — | 7:12 | |
mm | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | 1 | 1 | — | — | — | — | — |
Temp °C | 30 | 28 | 30 | 30 | 28 | 30 | 30 | 27 | 29 | 30 | 27 | 29 | 29 | 27 | 29 | 29 | 27 | 30 | 30 | 27 | 30 |
Feels °C | 34 | 33 | 34 | 34 | 33 | 33 | 34 | 32 | 33 | 34 | 32 | 34 | 33 | 33 | 34 | 34 | 33 | 34 | 34 | 32 | 34 |
Swell 1 Height (m) Direction Period (s) | SSW 8 | SSW 7 | SSW 8 | SSW 7 | SSW 7 | SW 7 | SSW 7 | E 9 | E 9 | E 10 | E 9 | SW 6 | E 9 | E 9 | E 9 | E 10 | E 10 | E 9 | ESE 10 | E 11 | E 12 |
134 | 91 | 178 | 114 | 68 | 53 | 30 | 41 | 39 | 48 | 42 | 19 | 44 | 59 | 60 | 64 | 70 | 40 | 36 | 57 | 69 | |
Swell 2 Height (m) Direction Period (s) | SE 10 | SSW 8 | ESE 10 | ESE 10 | E 10 | E 9 | E 9 | SSW 7 | SW 6 | SW 6 | SW 6 | E 9 | SW 6 | SW 6 | SW 6 | SW 6 | SSW 5 | ESE 11 | E 10 | SSW 5 | WSW 8 |
27 | 38 | 30 | 31 | 29 | 27 | 25 | 17 | 10 | 9 | 8 | 43 | 18 | 8 | 8 | 8 | 5 | 11 | 17 | 3 | 6 | |
Swell 3 Height (m) Direction Period (s) | E 9 | ESE 9 | SE 10 | SE 10 | SE 10 | SE 9 | SE 10 | SE 9 | SE 9 | SE 9 | SE 8 | SE 8 | ESE 5 | ESE 4 | SSE 9 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | ESE 11 |
15 | 17 | 17 | 15 | 15 | 14 | 15 | 14 | 13 | 12 | 11 | 10 | 5 | 2 | 7 | 7 | 7 | 7 | 6 | 6 | 12 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | NE 3 |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 42 | 9 | 9 | 75 | 9 | 9 | 238 | 9 | 9 | 284 | 9 | 9 | 638 | 9 | 9 | 20 | 9 | 20 | 42 | 9 | 9 |
Best forecast wave conditions in Shikoku | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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Information about the Monabe Rivermouth Surf forecast
The above surf forecast table for Monabe Rivermouth provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Monabe Rivermouth can be found by selecting the local surf guide option on the grey menu. Our Monabe 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 (Monabe 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 Monabe 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.
Monabe Rivermouth is 11 km (7 miles) from the city of Aki. If you plan a holiday in Shikoku, look for hotels and other accommodation in Aki. Aki has rooms for a wide range of budgets as well as car hire and transport links.











