Surf Forecasts:
Monabe Rivermouth surf forecast from 12 Jul 2026:
- Best quality surf: Sunday 19 Jul, 6PM (local time) - 6.5ft (2.0m), 11s period, ESE swell with glassy winds.
- Most powerful swell: Sunday 19 Jul, 3PM (local time) - 7ft (2.1m), 11s period, ESE swell with 990 kJ wave energy.
- Next surfable swell (1★+): Sunday 19 Jul, 12AM (local time) - 5ft (1.6m), 12s period with ESE swell.
Best Forecast Surf Conditions for Monabe Rivermouth this week:
The surf forecast for Monabe Rivermouth over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Sunday (Jul 19) at 12AM. The primary swell is predicted to be 1.6m and 12s period. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Monabe Rivermouth in the next 16 days are 2.1m 11s and forecast to arrive on Sunday (Jul 19) at 3PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.5m 13s period and expected on Sunday (Jul 12) at 9PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Sun 19th Jul) | 5ft (1.6m) 12s |
| Best Surf | 6PM (Sun 19th Jul) | 6.5ft (2.0m) 11s |
| Most Powerful | 3PM (Sun 19th Jul) | 7ft (2.1m) 11s |
Table - best surf conditions forecast for Monabe Rivermouth over the next 16 days.
Alright, Rusty here. Let me break it down.
To be honest, the first week and a half is flat as a pancake. We’re talking waves barely 1 foot, with weak energy readings in the 30s and 40s. Even with glassy wind, there’s nothing to ride. The period is mostly 9 to 12 seconds, but the height just isn’t there. Don’t even bother.
We get a pulse on Friday the 17th of July afternoon – a 3-foot swell from the ESE with a very long period of 17 seconds. The combined energy hits 464 (moderate), but the wind is onshore from the SSE at 9 mph, and the surf is still rated poor. The real issue is Monabe Rivermouth (Japan) “rarely breaks” and is “very sheltered” from swell. That long-period groundswell might just roll through without any push.
Saturday the 18th morning brings 4 feet from the ESE at 12 seconds, with energy at 888 (moderate). But the wind is cross-onshore from the SE at 6 mph, making it choppy. It’s a “marginal” one-out-of-ten day. That’s more of a kite-surf setup than a paddle.
The best window is Sunday the 19th of July morning. We’ve got 6 feet from the ESE (12-second period), clean glassy wind from the S at 3 mph, and combined energy of 796 (moderate). The swell is over 5 feet, too big for most beginners. The wave comment says “surfable but very ordinary.” With clear skies and glassy water, you could snag a few, but this spot “rarely breaks” so don’t get your hopes up.
After that, it fades. Monday the 20th through Wednesday the 22nd sees 4 feet down to 3 feet, with onshore or light wind and energy dropping to 172. Thursday the 23rd morning gives us 3 feet from the E at 12 seconds, glassy wind, energy of 292 (moderate), and another “surfable but ordinary” rating. A so-so window for a session.
Overall, there’s no stand-out day. The best bet is Sunday the 19th morning, and it’s just barely worth it. The rest is flat or junk. Water temp is 78°F, about average for this time of year (anomaly -0.8°C). For a spot that’s rarely breaking and sheltered, this long dry spell is normal. Forecasts can shift, but as it sits, I’d leave the stick at home.
Rusty.
Short Range ForecastMostly dry. Warm (max 30°C on Mon morning, min 26°C on Sun night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 7mm), mostly falling on Thu morning. Warm (max 30°C on Wed afternoon, min 25°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Sun 12 | Monday 13 | Tuesday 14 | Wednesday 15 | Thursday 16 | Friday 17 | Saturday 18 | |||||||||||||||
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) | SSW 14 | E 9 | SE 10 | SE 10 | SE 10 | SE 12 | SE 12 | SE 12 | SE 11 | SE 10 | ESE 10 | ESE 9 | ESE 9 | ESE 9 | SE 10 | ESE 17 | ESE 15 | ESE 12 | ESE 13 | ESE 12 | ESE 12 |
Wave Graph  | |||||||||||||||||||||
 kJ | 0 | 16 | 17 | 17 | 16 | 22 | 22 | 21 | 18 | 27 | 31 | 29 | 29 | 28 | 15 | 437 | 869 | 508 | 852 | 754 | 767 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | glassy | glassy | on | off | glassy | on | glassy | glassy | on | glassy | glassy | on | glassy | glassy | on | cross-on | cross-on | cross-on | cross-off | glassy |
High Tide | 5:16PM1.70m | 3:56AM1.73m | 6:05PM1.79m | 4:52AM1.81m | 6:48PM1.85m | 5:43AM1.87m | 7:28PM1.86m | 6:33AM1.89m | 8:05PM1.84m | 7:20AM1.86m | 8:40PM1.80m | 8:08AM1.78m | 9:12PM1.74m | 8:56AM1.65m | |||||||
Low Tide | 10:35PM1.06m | 11:01AM-0.00m | 11:28PM1.00m | 11:51AM-0.09m | 00:14AM0.93m | 12:37PM-0.11m | 00:58AM0.86m | 1:21PM-0.05m | 1:40AM0.79m | 2:01PM0.07m | 2:22AM0.74m | 2:40PM0.24m | 3:06AM0.70m | ||||||||
 |  |  | | | | |  | | | |  |  | | | |  | | |  | | |
 | — | — | 5:03 | — | — | 5:03 | — | — | 5:05 | — | — | 5:05 | — | — | 5:05 | — | — | 5:07 | — | — | 5:07 |
 | 7:16 | — | — | 7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:15 | — | — | 7:14 | — | 7:14 |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | 1 | — | — | 2 | 3 | — | 1 | 1 | — |
Temp °C | 28 | 26 | 30 | 30 | 28 | 30 | 29 | 28 | 30 | 30 | 28 | 30 | 29 | 28 | 29 | 29 | 27 | 28 | 28 | 26 | 28 |
Feels °C | 33 | 32 | 34 | 35 | 33 | 34 | 33 | 33 | 34 | 34 | 33 | 34 | 33 | 33 | 34 | 33 | 32 | 31 | 31 | 31 | 30 |
Swell 1 Height (m) Direction Period (s) | SSW 14 | SSW 12 | SSW 12 | SSW 11 | SSW 10 | SSW 10 | SSW 10 | SSW 9 | SSW 9 | SSW 9 | SSW 8 | SSW 7 | SSW 7 | SSW 6 | SSW 7 | ESE 17 | ESE 15 | ESE 12 | ESE 13 | ESE 12 | ESE 12 |
| kJ | 3954 | 1743 | 966 | 745 | 478 | 307 | 197 | 146 | 90 | 86 | 76 | 105 | 81 | 26 | 30 | 437 | 869 | 508 | 852 | 754 | 767 |
Swell 2 Height (m) Direction Period (s) | — | E 9 | SE 10 | SE 10 | SE 10 | SE 12 | SE 12 | SE 12 | SE 11 | SE 10 | ESE 10 | ESE 9 | ESE 9 | ESE 9 | E 8 | SSW 7 | E 9 | ESE 14 | SSW 7 | SSW 7 | SSW 7 |
| kJ | — | 16 | 17 | 17 | 16 | 22 | 22 | 21 | 18 | 27 | 31 | 29 | 29 | 28 | 12 | 30 | 41 | 371 | 10 | 5 | 5 |
Swell 3 Height (m) Direction Period (s) | — | — | E 9 | E 9 | E 9 | E 9 | E 9 | E 9 | E 10 | E 9 | SE 11 | SE 10 | SE 10 | SSW 8 | SE 10 | E 9 | SW 10 | SW 10 | SW 9 | SW 9 | SSW 7 |
| kJ | — | — | 15 | 15 | 15 | 15 | 15 | 15 | 16 | 15 | 18 | 16 | 15 | 12 | 15 | 27 | 4 | 4 | 3 | 3 | 5 |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | S 4 | S 4 | — | — | E 5 |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 13 | 9 | — | — | 29 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 42 | 9 | 9 | 9 | 9 | 9 | 42 | 9 | 9 | 42 | 9 | 9 | 42 | 9 | 9 | 50 | 20 | 20 | 515 | 0 | 0 |
Best forecast wave conditions in Shikoku | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Monabe Rivermouth surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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.
Nearest