Surf Forecasts:
Asakawa surf forecast from 16 Aug 2026:
- Best quality surf: Friday 21 Aug, 6AM (local time) - 3.5ft (1.0m), 11s period, S swell with glassy winds.
- Most powerful swell: Monday 24 Aug, 9AM (local time) - 5.5ft (1.7m), 17s period, SE swell with 1,690 kJ wave energy.
- Next surfable swell (1★+): Tuesday 18 Aug, 12AM (local time) - 2.5ft (0.7m), 9s period with SE swell.
Best Forecast Surf Conditions for Asakawa this week:
The surf forecast for Asakawa over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Aug 18) at 12AM. The primary swell is predicted to be 0.7m and 9s period with a secondary swell of 0.4m and 8s. 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 Asakawa in the next 16 days are 1.7m 17s and forecast to arrive on Monday (Aug 24) at 9AM. Winds are predicted to be cross-onshore at the time the swell arrives.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 12AM (Tue 18th Aug) | 2.5ft (0.7m) 9s |
| Best Surf | 6AM (Fri 21st Aug) | 3.5ft (1.0m) 11s |
| Most Powerful | 9AM (Mon 24th Aug) | 5.5ft (1.7m) 17s |
Table - best surf conditions forecast for Asakawa over the next 16 days.
The Lowdown
Right, folks, Rusty here. Gotta be straight with you – the next week or so is a bit of a write-off. The first week, from Monday the 17th through to the end of Sunday the 23rd of August, is looking pretty ordinary. We’ve got tiny, weak swell and the winds are mostly onshore or cross-onshore, so the conditions are gonna be poor.
We see a bit of a pulse picking up on Friday the 21st, with a small S swell around 4ft pushing the wave energy into the moderate range (315), but it’s coupled with onshore winds and even then it’s only rated as marginal. Don’t get too excited.
The real story starts Monday the 24th. We get our first taste of proper energy with a 6ft SE groundswell, but the cross-onshore wind and the "gentle cross-onshore and fairly choppy" description will spoil the party. The wave energy is ramping up hard though, hitting strong levels (2235). By Tuesday the 25th, we’re in business. That’s the standout window.
For the experienced crew, Tuesday morning the 25th of August at Asakawa is where the magic happens. We’re looking at a solid 12ft SSE groundswell with a very long 16-second period, and the wind is offering up glassy, clean conditions. The combined energy is pumping at a very strong 5383, and the experts are the only ones who should be looking at this. It’s a point break so that long-period energy will wrap in nicely, shaping up proper barrels, but with that size, it turns into a serious paddle too.
Wednesday morning the 26th is your next best bet, another 12ft SSE swell with a long 14-second period and glassy conditions again. Another solid option for the advanced surfer. The water temp is sitting at a normal 83°, so boardies and a rashie are all you need.
There’s a bit of a drop-off in quality towards the end of the week, with the swell holding size but the winds turning cross-onshore and making things a bit lumpy. It’s still big, with the swell sticking around 10ft, but the clean lines from Tuesday and Wednesday morning will be gone.
You get a second shot at something epic right at the tail end of the forecast. Monday the 31st of August, look out for a huge 13ft SE groundswell with a very long 17-second period heading in, and the wave energy is off the charts at 8968. The conditions are better in the morning with light cross-onshore winds. Then it gets even bigger on Monday afternoon, hitting 16ft and a massive 14178 energy reading. That is pure weapon-grade swell, expert only. This is a long-range outlook, so while it looks promising on the charts, take it with a pinch of salt for now.
Stay safe, stay stoked.
Rusty
Short Range ForecastLight rain (total 8mm), mostly falling on Mon night. Warm (max 29°C on Mon afternoon, min 25°C on Mon night). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 11mm), heaviest on Thu afternoon. Warm (max 29°C on Fri afternoon, min 25°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | |||||||||||||||
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) | SE 5 | SE 11 | SE 9 | SE 11 | SE 10 | SE 10 | ESE 8 | SE 10 | SE 10 | E 7 | S 9 | ESE 11 | S 10 | S 10 | S 10 | S 10 | S 9 | SSW 9 | SSW 9 | SSW 9 | SE 14 |
Wave Graph | |||||||||||||||||||||
47 | 30 | 79 | 29 | 28 | 27 | 71 | 27 | 25 | 45 | 52 | 86 | 264 | 284 | 290 | 235 | 180 | 153 | 110 | 94 | 322 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | glassy | on | on | cross-on | cross-on | on | glassy | cross-on | on | glassy | on | on | glassy | on | cross-on | cross-on | cross-on | cross-on | cross |
High Tide | 8:38PM1.72m | 9:14AM1.51m | 9:01PM1.65m | 10:05AM1.37m | 9:25PM1.57m | 11:17AM1.25m | 9:52PM1.48m | 2:05PM1.21m | 10:36PM1.39m | 4:20PM1.32m | 00:36AM1.34m | 4:43PM1.42m | 2:31AM1.38m | ||||||||
Low Tide | 2:29PM0.58m | 3:02AM0.48m | 2:55PM0.76m | 3:42AM0.53m | 3:19PM0.92m | 4:31AM0.59m | 3:42PM1.07m | 5:42AM0.66m | 4:07PM1.20m | 7:28AM0.66m | 8:19PM1.26m | 8:57AM0.58m | 9:51PM1.18m | ||||||||
5:24 | — | — | 5:26 | — | — | 5:26 | — | — | 5:26 | — | — | 5:28 | — | — | 5:28 | — | — | 5:28 | — | — | |
— | 6:46 | — | — | 6:45 | — | — | 6:45 | — | — | 6:44 | — | — | 6:43 | — | — | 6:40 | — | — | 6:39 | — | |
mm | 2 | — | 4 | 1 | — | — | — | — | 1 | 2 | 6 | 1 | 1 | — | — | 1 | — | — | 2 | 1 | — |
Temp °C | 28 | 29 | 26 | 28 | 28 | 26 | 28 | 28 | 26 | 28 | 28 | 26 | 28 | 29 | 26 | 29 | 29 | 26 | 28 | 29 | 26 |
Feels °C | 30 | 32 | 31 | 31 | 31 | 31 | 31 | 32 | 31 | 33 | 33 | 31 | 32 | 33 | 31 | 32 | 32 | 30 | 30 | 32 | 30 |
Swell 1 Height (m) Direction Period (s) | SSW 8 | SE 5 | SE 9 | SE 11 | SE 5 | SE 5 | ESE 8 | ESE 8 | ESE 5 | ESE 7 | S 9 | S 8 | S 10 | S 10 | S 10 | S 10 | S 9 | SSW 9 | SSW 9 | SSW 9 | SE 14 |
22 | 30 | 79 | 29 | 23 | 23 | 71 | 19 | 24 | 25 | 52 | 86 | 264 | 284 | 290 | 235 | 180 | 153 | 110 | 94 | 322 | |
Swell 2 Height (m) Direction Period (s) | SE 11 | SSW 8 | SSW 8 | SSW 8 | ESE 8 | ESE 8 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | ESE 4 | ESE 11 | ESE 11 | ESE 11 | ESE 10 | ESE 10 | ESE 10 | ESE 11 | ESE 11 | SSW 9 |
42 | 21 | 20 | 11 | 22 | 23 | 26 | 26 | 25 | 25 | 25 | 7 | 44 | 44 | 44 | 42 | 42 | 21 | 37 | 22 | 84 | |
Swell 3 Height (m) Direction Period (s) | ESE 9 | SE 11 | SE 11 | — | SE 10 | SE 10 | SSW 8 | SSW 8 | E 7 | S 9 | — | SE 10 | ESE 6 | E 8 | E 14 | ESE 7 | ESE 7 | ESE 6 | SSE 10 | SE 13 | S 10 |
28 | 30 | 30 | — | 28 | 27 | 11 | 11 | 4 | 25 | — | 28 | 7 | 23 | 4 | 10 | 10 | 4 | 9 | 46 | 2 | |
Wind waves Height (m) Direction Period (s) | SE 5 | — | SE 4 | SE 4 | — | — | — | SE 5 | — | E 7 | ESE 5 | ESE 11 | — | — | — | — | — | — | — | — | — |
47 | — | 21 | 21 | — | — | — | 27 | — | 45 | 13 | 75 | — | — | — | — | — | — | — | — | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 43 | 475 | 0 | 43 | 522 | 14 | 19 | 11 | 2 | 64 | 11 | 0 | 19 | 11 | 0 | 11 | 30 | 2 | 336 | 11 | 2 |
Best forecast wave conditions in Shikoku | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
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Information about the Asakawa Surf forecast
The above surf forecast table for Asakawa provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Asakawa can be found by selecting the local surf guide option on the grey menu. Our Asakawa 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 (Asakawa) 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 Asakawa 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.
Are you planning a holiday in Shikoku? If you are looking for accommodation near Asakawa, camping, hotels and holiday cottages in Shikoku, consider staying in Anan which is 41 km (25 miles) away. Other places in and around Shikoku where you can find information about places to rent, and car hire include Muroto which is 44 km (27 miles) away, Komatsushima, Aki and Kamojima.











