Surf Forecasts:
Monabe Rivermouth surf forecast from 2 Aug 2026:
- Best quality surf: Thursday 6 Aug, 6AM (local time) - 23ft (7.0m), 18s period, SE swell with cross-offshore winds.
- Most powerful swell: Thursday 6 Aug, 3PM (local time) - 25ft (7.5m), 17s period, SE swell with 34,010 kJ wave energy.
- Next surfable swell (1★+): Sunday 2 Aug, 6PM (local time) - 4ft (1.2m), 16s 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 (Aug 02) at 6PM. The primary swell is predicted to be 1.2m and 16s period. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Monabe Rivermouth in the next 16 days are 7.5m 17s and forecast to arrive on Thursday (Aug 06) at 3PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 4.5m 16s period and expected on Saturday (Aug 08) at 3PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6PM (Sun 2nd Aug) | 4ft (1.2m) 16s |
| Best Surf | 6AM (Thu 6th Aug) | 23ft (7.0m) 18s |
| Most Powerful | 3PM (Thu 6th Aug) | 25ft (7.5m) 17s |
Table - best surf conditions forecast for Monabe Rivermouth over the next 16 days.
The Lowdown
G’day, Rusty here. We’ve got a wild 16-day window ahead for Monabe Rivermouth. The whole run kicks off with a small, clean wave and builds into a massive, late-week pulse of swell. But this break is a rare, sheltered river mouth that needs the right conditions. The opening session is tiny, but then things go from mellow to monstrous in a hurry.
Sunday morning, 2 August, starts us off with a tiny 2ft swell out of the ESE. It’s glassy, the combined energy is moderate at 373, and the water’s a touch warmer than normal at 85°, but this is a very sheltered spot, so that 2ft is going to feel even smaller. The wave is surfable but the conditions are ordinary. On Monday the 3rd, we've got a bit more size, 5ft from the ESE (combined energy 1380), and it’s glassy again in the morning. This is better, but still just a fun little wave. Then Tuesday morning on the 4th picks up with a solid 8ft ESE swell, pure glass, and the energy jumps to 3705. That’s where it starts to get interesting.
Wednesday morning, 5 August, is the standout. This is the one to circle. The swell hits 16ft out of the ESE, the combined energy is a massive 14571, and the wind is dead calm, glassy. This is serious power for experienced surfers only. Beginners, stay out. This period is over 15 seconds, a very long groundswell. For a sheltered river mouth, that long-period energy tends to push in straight and can be tricky, but when it lines up, it’s next-level. The afternoon stays big at 18ft but gets a messy cross-onshore wind. Thursday the 6th stays huge, 25ft from the SE, with combined energy over 35,000. The morning has a cross-offshore breeze keeping it clean, but that’s expert-only territory. Wind gets stiff and messy later.
Friday the 7th and Saturday the 8th still have huge swell, 20-23ft, but the wind stays cross or cross-off, making things lumpy or just marginal. The swell drops by Saturday afternoon, and from there it’s a slow fade into small, messy, or poor conditions through the second week. Monday the 10th onward, we’re back to weak, short-period slop and poor surf. There’s a little glassy bump on the 11th and 12th with 3-6ft, but it’s ordinary and short-period. After that, the 13th to the 17th of August is just tiny, with combined energy down to double digits, and the rest is basically flat or blown out. A week-plus of flatness is normal for a sheltered river mouth like this, so don’t stress. Forecasts can change, but right now it’s a long wait.
- Rusty
Short Range ForecastLight rain (total 5mm), mostly falling on Mon afternoon. Warm (max 32°C on Sun morning, min 25°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummarySome drizzle, heaviest during Fri night. Warm (max 33°C on Thu morning, min 27°C on Wed night). Winds increasing (calm on Wed morning, fresh winds from the E by Fri morning). | ||||||||||||||||||||
Sunday 2 | Monday 3 | Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | |||||||||||||||
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 18 | ESE 16 | ESE 15 | ESE 16 | ESE 16 | ESE 17 | ESE 16 | ESE 17 | ESE 17 | ESE 17 | ESE 17 | SE 17 | SE 18 | SE 17 | SE 16 | SSE 16 | SSE 16 | S 16 | S 16 | ESE 9 | ESE 9 |
Wave Graph  | |||||||||||||||||||||
 kJ | 240 | 671 | 696 | 1360 | 1697 | 2895 | 3277 | 4701 | 11422 | 14571 | 18245 | 24794 | 31880 | 34010 | 31399 | 23833 | 18625 | 14642 | 14068 | 1242 | 1960 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | off | glassy | cross-on | cross | glassy | on | off | glassy | cross-on | cross-off | cross-off | cross | cross-off | cross | cross | cross-off | cross-off | cross | cross |
High Tide | 8:28PM1.77m | 8:20AM1.68m | 8:54PM1.75m | 9:05AM1.58m | 9:23PM1.72m | 10:00AM1.47m | 9:57PM1.67m | 11:18AM1.36m | 10:41PM1.60m | 1:19PM1.32m | 11:46PM1.54m | 3:23PM1.42m | 1:20AM1.53m | ||||||||
Low Tide | 2:03PM0.30m | 2:26AM0.61m | 2:33PM0.43m | 3:05AM0.57m | 3:05PM0.59m | 3:51AM0.55m | 3:42PM0.77m | 4:49AM0.54m | 4:29PM0.96m | 6:05AM0.52m | 5:47PM1.13m | 7:38AM0.45m | 8:01PM1.21m | ||||||||
 | |  | |  |  |  |  |  | | | | | | | | |  |  | | | |
 | 5:16 | — | — | 5:16 | — | — | 5:18 | — | — | 5:18 | — | — | 5:20 | — | — | 5:20 | — | — | 5:20 | — | — |
 | — | 7:04 | — | — | 7:02 | — | — | 7:01 | — | — | 7:01 | — | — | 7:00 | — | — | 7:00 | — | — | 6:59 | — |
mm | — | — | — | — | 2 | 2 | 1 | — | — | — | — | — | — | — | — | — | — | 1 | 7 | 4 | 36 |
Temp °C | 32 | 31 | 29 | 31 | 30 | 27 | 28 | 28 | 27 | 31 | 32 | 28 | 33 | 32 | 29 | 31 | 31 | 28 | 27 | 27 | 27 |
Feels °C | 36 | 35 | 33 | 35 | 33 | 32 | 33 | 32 | 30 | 33 | 33 | 31 | 32 | 31 | 29 | 30 | 30 | 29 | 30 | 29 | 29 |
Swell 1 Height (m) Direction Period (s) | ESE 18 | ESE 16 | ESE 15 | ESE 16 | ESE 16 | ESE 17 | ESE 16 | ESE 17 | ESE 17 | ESE 17 | ESE 17 | SE 17 | SE 18 | SE 17 | SE 16 | SSE 16 | SSE 16 | S 16 | S 16 | SSW 16 | SSW 16 |
| kJ | 240 | 671 | 696 | 1360 | 1697 | 2895 | 3277 | 4701 | 11422 | 14571 | 18245 | 24794 | 31880 | 34010 | 27828 | 23833 | 18625 | 14642 | 14068 | 10617 | 9481 |
Swell 2 Height (m) Direction Period (s) | E 14 | SE 10 | SE 10 | SE 10 | S 8 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SSE 10 | — |
| kJ | 104 | 28 | 15 | 15 | 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 588 | — |
Swell 3 Height (m) Direction Period (s) | SE 9 | SSW 8 | SSW 8 | S 8 | S 8 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 29 | 7 | 6 | 5 | 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | NE 4 | — | E 4 | ESE 6 | E 7 | E 8 | ESE 9 | — | — | — | — | E 11 | E 10 | SE 16 | E 10 | E 9 | ESE 10 | ESE 10 | ESE 9 | ESE 9 |
| kJ | — | 6 | — | 13 | 110 | 262 | 428 | 573 | — | — | — | — | 3352 | 2533 | 31399 | 2719 | 1566 | 2365 | 1532 | 1242 | 1960 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 42 | 0 | 0 | 20 | 20 | 0 | 20 | 0 | 0 | 1670 | 0 | 387 | 515 | 550 | 550 | 515 | 528 | 559 | 515 | 550 |
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)
Latest Updates
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