
Surf Forecasts:
Monabe Rivermouth surf forecast from 19 Jul 2026:
- Best quality surf: Sunday 26 Jul, 6PM (local time) - 2ft (0.6m), 13s period, SSE swell with glassy winds.
- Most powerful swell: Monday 27 Jul, 3AM (local time) - 4ft (1.2m), 12s period, S swell with 418 kJ wave energy.
- Next surfable swell (1★+): Sunday 26 Jul, 6PM (local time) - 2ft (0.6m), 13s period with SSE 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 26) at 6PM. The primary swell is predicted to be 0.6m and 13s period with a secondary swell of 0.5m and 11s. Another secondary swell of 0.4m and 3s is also forecast. 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 1.2m 12s and forecast to arrive on Monday (Jul 27) 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 0.3m 7s period and expected on Tuesday (Jul 21) at 3AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 6PM (Sun 26th Jul) | 2ft (0.6m) 13s |
| Best Surf | 6PM (Sun 26th Jul) | 2ft (0.6m) 13s |
| Most Powerful | 3AM (Mon 27th Jul) | 4ft (1.2m) 12s |
Table - best surf conditions forecast for Monabe Rivermouth over the next 16 days.
The Lowdown
Alright, this is Rusty, and I've got to level with you – it's been a quiet stretch out here at Monabe Rivermouth. We're looking at a solid week of tiny, weak waves with very ordinary conditions before anything worthwhile shows up. The modest energy that's around is from the east or southeast, but it's barely registering. Combined wave energy is sitting in the low double digits to around 80 for most of this first week, so we're talking about nothing to get excited about until later.
Starting Monday the 20th, there's just no surf to speak of. We've got glassy mornings and light offshore winds a few times, but with swell height only 0.6 to 2 ft and periods around 9 to 11 seconds, it's a flat spell. The afternoons see a light onshore breeze that won't help anything. This pattern of poor surf holds right through until the morning of Sunday the 26th. Even with a bit more energy on that Sunday (combined energy around 141), the swell height is still a tiny 1 ft. A long, flat run.
The tide starts to turn properly on Monday the 27th of July. The morning session is where it gets interesting first – we finally get a 4 ft swell from the SSE with a period of 12 seconds, giving a decent kick of energy (682). It's glassy, light wind, and the waves are just about surfable. The afternoon picks up to 5 ft from the south (energy climbs to 1273) but there’s risk of thunderstorms and a light onshorer, making it a bit messy.
But the real standout, the one to circle on your calendar, is Tuesday the 28th. Holy mackerel. Tuesday morning is the pick of the whole outlook. A solid 10 ft groundswell from the south with a very long 15-second period is pumping in. Combined energy is a massive 4408 – strong wave energy, no doubt. On top of that, it's glassy, the wind is offshore from the SSE, and conditions are described as excellent for experienced surfers. This is a big-swell day for sure – well over 8 ft – so it's strictly for the experienced crew. The afternoon stays big at 12 ft but picks up a light onshore wind, so morning is your window for clean, powerful waves.
After that, it's a rollercoaster. Wednesday the 29th drops right off again into weak, small surf with onshore winds. Then we go into a dodgy period with risk of thunderstorms and strong cross-onshore winds whipping up from the ESE at 12-18 mph through Thursday and Friday the 30th and 31st. Swell is tiny and junked out.
Then things get wild but wrong. Saturday the 1st of August, the morning swell is only 6 ft but with a short, weak period of 6 seconds and a howling 22 mph cross-on shore – it'll be a washing machine. The afternoon, though, is massive – 18 ft from the south at 14 seconds – that’s a huge amount of energy (12695!) – but with onshore winds. The same story for Sunday the 2nd of August: absolute beast swells (20 ft, 16 ft) but cross-onshore winds from the southeast or south at 15-18 mph. With the wind hammering it, this setup is way more interesting for kite surfing than paddle surfing. It's just blown-out mayhem for a surfer. That big swell will be breaking straight and ugly at a river mouth.
So, to sum it up: there's a lot of flat and a lot of windy junk in this 16-day window. The single standout that's worth the paddle is the morning of Tuesday, 28th July. Get on it early if you're an experienced surfer after some clean, heavy south groundswell at Monabe Rivermouth.
That's it from me. Stay frothy, but pick your battles.
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 SummaryMostly dry. Warm (max 31°C on Sat morning, min 27°C on Wed night). Wind will be generally light. | ||||||||||||||||||
Monday 20 | Tuesday 21 | Wednesday 22 | Thursday 23 | Friday 24 | Saturday 25 | ||||||||||||||
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) | E 10 | E 9 | E 9 | E 9 | E 11 | ESE 11 | ESE 10 | E 10 | E 10 | E 10 | E 10 | SE 10 | SE 18 | SE 18 | SE 18 | SE 16 | SE 16 | SE 16 | SE 16 |
Wave Graph | |||||||||||||||||||
44 | 60 | 60 | 60 | 58 | 37 | 21 | 32 | 31 | 18 | 18 | 17 | 51 | 49 | 49 | 42 | 91 | 90 | 87 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | glassy | on | glassy | glassy | on | glassy | cross-on | on | glassy | glassy | on | glassy | glassy | on | glassy | glassy | on | glassy |
High Tide | 9:43PM1.69m | 9:48AM1.51m | 10:14PM1.63m | 10:51AM1.37m | 10:46PM1.56m | 12:17PM1.26m | 11:25PM1.51m | 2:21PM1.26m | 00:20AM1.46m | 4:03PM1.34m | 1:37AM1.44m | 4:53PM1.44m | 2:50AM1.47m | ||||||
Low Tide | 3:52AM0.67m | 3:50PM0.66m | 4:44AM0.67m | 4:25PM0.85m | 5:45AM0.66m | 5:07PM1.03m | 6:59AM0.64m | 6:19PM1.16m | 8:17AM0.59m | 8:22PM1.21m | 9:22AM0.50m | 9:48PM1.18m | |||||||
— | 5:07 | — | — | 5:09 | — | — | 5:09 | — | — | 5:09 | — | — | 5:11 | — | — | 5:11 | — | — | |
7:14 | — | 7:13 | — | — | 7:13 | — | — | 7:12 | — | — | 7:10 | — | — | 7:10 | — | — | 7:09 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 30 | 30 | 28 | 30 | 29 | 27 | 30 | 30 | 27 | 30 | 30 | 27 | 30 | 30 | 27 | 31 | 30 | 28 |
Feels °C | 33 | 34 | 34 | 34 | 35 | 33 | 33 | 34 | 35 | 33 | 35 | 35 | 33 | 35 | 34 | 32 | 35 | 34 | 34 |
Swell 1 Height (m) Direction Period (s) | E 10 | E 9 | E 9 | E 9 | E 11 | ESE 11 | E 8 | E 10 | E 10 | E 10 | E 10 | SE 10 | E 10 | SE 10 | SE 18 | SE 11 | SE 11 | SE 10 | SE 10 |
44 | 60 | 60 | 60 | 58 | 37 | 12 | 32 | 31 | 18 | 18 | 15 | 17 | 14 | 49 | 41 | 41 | 37 | 49 | |
Swell 2 Height (m) Direction Period (s) | SE 5 | SSE 9 | SSE 8 | SSE 8 | SSE 8 | E 8 | ESE 10 | ESE 10 | ESE 11 | ESE 10 | SE 9 | E 10 | SE 10 | SE 18 | SE 9 | SE 16 | SE 16 | SE 16 | SE 16 |
5 | 7 | 7 | 7 | 7 | 21 | 21 | 11 | 11 | 10 | 14 | 17 | 16 | 49 | 14 | 42 | 91 | 90 | 87 | |
Swell 3 Height (m) Direction Period (s) | SE 9 | SSW 5 | ESE 11 | SSW 7 | SSW 8 | SSE 8 | ENE 11 | SSE 8 | SSE 8 | SSE 8 | SSW 3 | SE 19 | SE 18 | E 10 | E 9 | E 9 | SSW 8 | SSW 7 | SSW 7 |
13 | 3 | 13 | 5 | 6 | 6 | 12 | 6 | 6 | 6 | 1 | 15 | 51 | 17 | 15 | 15 | 11 | 10 | 11 | |
Wind waves Height (m) Direction Period (s) | — | — | SSW 5 | SW 4 | — | — | — | — | SSW 3 | SSW 3 | — | SSW 3 | SW 3 | — | — | SSW 4 | — | — | SW 2 |
— | — | 2 | 3 | — | — | — | — | 1 | 1 | — | 1 | 2 | — | — | 1 | — | — | 1 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 9 | 9 | 640 | 9 | 9 | 302 | 42 | 9 | 490 | 235 | 47 | 638 | 9 | 9 | 42 | 9 | 9 | 50 | 9 |
Best forecast wave conditions in Shikoku | |||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||
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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.










