Surf Forecasts:
Ikumi Beach surf forecast from 18 Aug 2026:
- Best quality surf: Tuesday 25 Aug, 6PM (local time) - 5.5ft (1.7m), 13s period, SE swell with glassy winds.
- Most powerful swell: Tuesday 25 Aug, 6PM (local time) - 5.5ft (1.7m), 13s period, SE swell with 1,006 kJ wave energy.
- Next surfable swell (1★+): Tuesday 18 Aug, 9PM (local time) - 2.5ft (0.7m), 8s period with SE swell.
Best Forecast Surf Conditions for Ikumi Beach this week:
The surf forecast for Ikumi Beach over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Aug 18) at 9PM. The primary swell is predicted to be 0.7m and 8s period with a secondary swell of 0.4m and 10s. Another secondary swell of 0.8m and 4s is also forecast. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Ikumi Beach in the next 16 days are 1.7m 13s and forecast to arrive on Tuesday (Aug 25) at 6PM. Winds are predicted to be glassy at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 9s period and expected on Tuesday (Aug 25) at 12AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Tue 18th Aug) | 2.5ft (0.7m) 8s |
| Best Surf | 6PM (Tue 25th Aug) | 5.5ft (1.7m) 13s |
| Most Powerful | 6PM (Tue 25th Aug) | 5.5ft (1.7m) 13s |
Table - best surf conditions forecast for Ikumi Beach over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at the next couple of weeks for this stretch of coast.
The short version is that the next few days are going to be a bit of a write-off. The swell is tiny, mostly short-period windswell, and a lot of it is coming from the wrong direction. You won't be missing anything until late next week if you have other things to do. But hold on to your board shorts, because the middle of next week is looking like something special.
Right now, Tuesday the 18th, it's stormy, onshore, and the swell is a weak 3ft at 5 seconds. The energy reading is poor (86), and it’s just messy. Wednesday the 19th is more of the same – small, onshore, and not worth the paddle. We finally see a bit of glass on Thursday morning the 20th, but the swell is gone – down to 1ft with weak energy (66). You might get a knee-high slop fest, but it’s not what I’d call a surf. Friday morning the 21st starts to show a pulse of energy (202), but still only 3ft and a bit inconsistent. Glassy, which is nice, but just not enough juice. That period through to Sunday the 23rd stays pretty weak, with the swell dropping to 2ft and energy slipping back down to the low 100s. It's flat-ish.
Now, here’s where it gets interesting. The swell really starts to fill in on Monday the 24th. There’s a big jump in the energy reading (731) that morning, and that long-period SE groundswell at 16 seconds starts to show. Even though it’s only 3ft at first, that long period means there’s some proper power behind it. The wind is light and glassy, which is ideal. This is the start of the good stuff. Monday afternoon it jumps to 5ft and the energy is pumping (1381). This is the one to watch.
From Tuesday the 25th, just be careful. The swell is not only getting bigger, it’s getting too big for this spot. We're looking at 8ft on Tuesday morning with energy reading over 3700, and by Tuesday afternoon it’s 10ft (4093). This is clean and big, but it’s not for the faint of heart. This size is getting into the expert zone. The energy keeps climbing all week – Wednesday the 26th sees 10-13ft (8004), and by Thursday the 27th it’s 15ft (9356). This is a serious, powerful groundswell. The wind is going to be a factor on the 27th, with some cross-shore breeze, but it’s still big.
There is a brief cleanup on Friday the 28th when the wind drops to calm and glassy early, but the swell is a solid 13ft (5854). This is only for the most experienced. It stays in that 8ft to 10ft range over the weekend and into Monday the 31st. The wind turns offshore on the Monday morning and the wave comment says it's excellent for experienced surfers. That’s your window if you have the skills and the courage. By Tuesday the 1st of September, it’s still overhead at 7ft with excellent conditions and offshore winds, but it's still a solid, committed size.
So, the standout here is clearly Monday the 24th. As the new swell starts to build in the morning, it will be the best combo of size, power, and clean conditions before it gets too unruly. The other one is the morning of Monday the 31st, when the swell drops back to a still-chunky 8ft, but the conditions are glassy and the wind is offshore. That’s a proper session.
Remember, this is Ikumi Beach, an exposed beach break. It’s rated for beginners when it’s small, but with the size on the cards from August 25th, it gets heavy and way out of that league. The long periods (15-17 seconds) are great for power and shape, but at a beach break like this, they can make the waves break a bit too straight, so be ready for that. Also, the water temp is a normal 83°, so no worries there.
The wind and tide on a couple of those big days look favorable, which is why the call is for it to be too big, not just messy. For the average punter, this is a kite-surfing sort of swell mid-week. For the brave, there are some epic, giant waves to be had. Stay safe out there.
Rusty.
Short Range ForecastLight rain (total 9mm), mostly falling on Tue afternoon. Warm (max 30°C on Fri morning, min 24°C on Wed night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 30°C on Sat morning, min 25°C on Fri night). Wind will be generally light. | |||||||||||||||||||
Tue 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | ||||||||||||||
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 5 | SE 8 | ESE 8 | ESE 8 | SE 10 | SE 10 | SE 10 | S 9 | S 9 | S 10 | S 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SE 9 |
Wave Graph | ||||||||||||||||||||
36 | 69 | 56 | 51 | 29 | 25 | 25 | 99 | 101 | 190 | 173 | 141 | 149 | 116 | 90 | 88 | 86 | 70 | 94 | 21 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | glassy | on | cross-on | glassy | glassy | cross-on | cross-off | glassy | cross | cross-off | glassy | cross-on | cross-off | glassy | cross-on | glassy | glassy | on | glassy |
High Tide | 8:58PM1.86m | 9:48AM1.68m | 9:27PM1.81m | 10:51AM1.55m | 10:01PM1.74m | 12:28PM1.45m | 10:49PM1.66m | 2:49PM1.47m | 00:11AM1.59m | 4:10PM1.59m | 2:01AM1.59m | 4:51PM1.70m | ||||||||
Low Tide | 3:27AM0.55m | 3:26PM0.93m | 4:16AM0.59m | 4:02PM1.10m | 5:20AM0.63m | 4:54PM1.26m | 6:46AM0.65m | 6:52PM1.37m | 8:20AM0.60m | 9:07PM1.34m | 9:32AM0.51m | 10:12PM1.22m | ||||||||
— | — | 5:26 | — | — | 5:26 | — | — | 5:28 | — | — | 5:28 | — | — | 5:30 | — | — | 5:30 | — | — | |
6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:42 | — | — | 6:39 | — | — | 6:38 | — | |
mm | 2 | 3 | 1 | 3 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 27 | 26 | 28 | 28 | 26 | 29 | 29 | 26 | 30 | 29 | 26 | 30 | 30 | 26 | 29 | 29 | 25 | 29 | 29 | 26 |
Feels °C | 31 | 31 | 32 | 33 | 32 | 32 | 33 | 31 | 33 | 32 | 30 | 33 | 33 | 30 | 32 | 31 | 29 | 33 | 33 | 31 |
Swell 1 Height (m) Direction Period (s) | SE 10 | SE 8 | ESE 8 | SE 10 | ESE 7 | ESE 7 | S 8 | S 9 | S 9 | S 10 | S 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SSW 9 | SE 10 | SW 9 |
28 | 69 | 56 | 26 | 29 | 18 | 21 | 99 | 101 | 190 | 173 | 141 | 149 | 116 | 90 | 88 | 86 | 70 | 49 | 90 | |
Swell 2 Height (m) Direction Period (s) | SSW 8 | SE 10 | SE 10 | SSW 8 | SE 10 | SE 10 | SE 10 | SE 11 | S 11 | ESE 11 | SE 11 | ESE 10 | SE 10 | ESE 10 | ESE 11 | SE 11 | ESE 11 | SE 10 | E 12 | SE 9 |
11 | 27 | 26 | 11 | 25 | 25 | 25 | 29 | 62 | 44 | 29 | 43 | 17 | 10 | 40 | 30 | 40 | 35 | 12 | 21 | |
Swell 3 Height (m) Direction Period (s) | ESE 8 | SSW 8 | SSW 8 | SW 9 | SSW 8 | S 8 | ESE 7 | ESE 7 | ESE 11 | E 6 | E 6 | ESE 6 | E 10 | ESE 13 | SSE 10 | SSE 9 | SSE 10 | ESE 12 | SE 5 | ESE 10 |
13 | 11 | 11 | 3 | 6 | 12 | 9 | 5 | 45 | 3 | 3 | 4 | 8 | 17 | 9 | 9 | 9 | 29 | 1 | 20 | |
Wind waves Height (m) Direction Period (s) | SE 5 | — | — | ESE 8 | — | — | — | — | — | — | SW 3 | — | — | SW 3 | — | SSW 3 | SW 3 | — | SSW 9 | SW 3 |
36 | — | — | 51 | — | — | — | — | — | — | 2 | — | — | 1 | — | 1 | 1 | — | 94 | 5 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 4 | 0 | 30 | 4 | 0 | 0 | 16 | 0 | 0 | 4 | 0 | 0 | 16 | 0 | 0 | 16 | 0 | 0 | 33 | 0 |
Best forecast wave conditions in Shikoku | ||||||||||||||||||||
Best forecast wave conditions in Japan | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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Information about the Ikumi Beach Surf forecast
The above surf forecast table for Ikumi Beach provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Ikumi Beach can be found by selecting the local surf guide option on the grey menu. Our Ikumi Beach 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 (Ikumi Beach) 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 Ikumi Beach 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.
Ikumi Beach is 30 km (19 miles) from Muroto. If you plan a holiday in Shikoku, look for hotels and other accommodation in Muroto. Muroto has rooms for a wide range of budgets as well as car hire and transport links.











