Surf Forecasts:
Asakawa surf forecast from 8 Sep 2026:
- Best quality surf: Wednesday 9 Sep, 12AM (local time) - 10ft (3.0m), 10s period, SSE swell with glassy winds.
- Most powerful swell: Wednesday 9 Sep, 9AM (local time) - 10ft (3.0m), 9s period, SSE swell with 1,414 kJ wave energy.
- Next surfable swell (1★+): Tuesday 8 Sep, 3PM (local time) - 6ft (1.8m), 9s period with S 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 (Sep 08) at 3PM. The primary swell is predicted to be 1.8m and 9s period with a secondary swell of 1.4m and 8s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Asakawa in the next 16 days are 3.0m 9s and forecast to arrive on Wednesday (Sep 09) at 9AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 5s period and expected on Wednesday (Sep 09) at 9PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 3PM (Tue 8th Sep) | 6ft (1.8m) 9s |
| Best Surf | 12AM (Wed 9th Sep) | 10ft (3.0m) 10s |
| Most Powerful | 9AM (Wed 9th Sep) | 10ft (3.0m) 9s |
Table - best surf conditions forecast for Asakawa over the next 16 days.
The Lowdown
Alright, let's break this down. The long-range models are screaming, but we've got some flat and funky weather to wade through first.
Tuesday morning starts small and junky, a 2ft south swell at Asakawa. It's cross and a bit lumpy. But the afternoon glass-off is your chance. That south swell builds to a clean 6ft as the wind goes dead. Water's a touch warm for this time of year at 83°. That's the first real window.
Wednesday throws a bigger, messier swell at us. A 10ft south-southeast push in the morning, but it's chopped up by a cross-onshore breeze and short period. The afternoon drops to 8ft, but the wind is still not right. Too much mess for the juice.
Thursday and Friday are pretty poor. Swell drops to 3-4ft. It's clean on Friday morning, but just small and weak. Not worth suiting up for.
The weekend is a total write-off. We're talking 2ft leftovers. There's a solid 3-4 day gap where you're better off finding something else to do.
A weak pulse hits Monday, September 14th, around 5ft from the east-southeast, but it's got onshore winds and gets all chopped up. Not great.
Now, for the headline act. The following Sunday, September 20th, you can see the energy starting to build. But it’s Monday, September 21st, when it all comes together. This is the standout.
We're looking at a serious 12-13ft southeast groundswell, with a period of 18 seconds. That's a proper, long-period groundswell. And it's coming in with a moderate offshore wind all day. This is a world-class event at Asakawa. There is so much water moving (8157 to 9827 on the energy scale), this is strictly for experts. 13 feet of clean, powerful swell is not a joke. If you're charging, this is the day.
It eases a bit on Tuesday the 22nd, still a solid 8-10ft from the east-southeast, with lighter winds going glassy by the afternoon. Still excellent, but a step down and better suited for the experienced crew.
After that, it just fades out into small, weak surf for the rest of the week.
So, that's the rundown. A slow, messy start, but a monstrous window on Monday the 21st. That's the one. Mark it down, but remember, it's a long way out and forecasts can change. Still, the potential here is huge.
- Rusty
Short Range ForecastHeavy rain (total 58mm), heaviest during Tue morning. Warm (max 28°C on Tue afternoon, min 21°C on Wed night). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 13mm), heaviest on Sat afternoon. Warm (max 28°C on Sun morning, min 24°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | |||||||||||||||
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) | S 9 | S 9 | SSE 10 | SSE 9 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 7 | SSE 7 | SSE 7 | E 14 | ESE 9 | ESE 9 | SE 9 | ESE 9 | SE 8 | ESE 9 |
Wave Graph  | |||||||||||||||||||||
 kJ | 327 | 539 | 1382 | 1414 | 785 | 243 | 188 | 184 | 171 | 123 | 145 | 94 | 52 | 40 | 35 | 47 | 59 | 83 | 328 | 295 | 313 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | glassy | glassy | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | glassy | glassy | glassy | glassy | cross | glassy | cross-on | on | cross-on | cross-on | on | glassy |
High Tide | 4:52PM1.68m | 3:59AM1.68m | 5:21PM1.76m | 4:49AM1.79m | 5:47PM1.81m | 5:34AM1.87m | 6:13PM1.84m | 6:15AM1.89m | 6:37PM1.84m | 6:54AM1.85m | 7:00PM1.83m | 7:31AM1.78m | 7:22PM1.79m | ||||||||
Low Tide | 9:55AM0.25m | 10:28PM0.91m | 10:41AM0.18m | 11:04PM0.73m | 11:20AM0.16m | 11:38PM0.57m | 11:55AM0.21m | 00:11AM0.43m | 12:27PM0.30m | 00:43AM0.33m | 12:57PM0.43m | 1:15AM0.29m | 1:24PM0.57m | 1:46AM0.29m | |||||||
 | |  | | |  |  |  | | | |  | | |  |  | |  | | |  | |
 | 5:39 | — | — | 5:41 | — | — | 5:41 | — | — | 5:41 | — | — | 5:43 | — | — | 5:43 | — | — | 5:43 | — | — |
 | — | 6:19 | — | — | 6:17 | — | — | 6:16 | — | — | 6:15 | — | — | 6:14 | — | — | 6:13 | — | — | 6:10 | — |
mm | 19 | 9 | 12 | 5 | 6 | 5 | 1 | — | 1 | 1 | 2 | — | 1 | 4 | — | — | 1 | 4 | 1 | — | 6 |
Temp °C | 26 | 28 | 27 | 27 | 27 | 22 | 23 | 23 | 23 | 25 | 25 | 24 | 26 | 26 | 25 | 28 | 28 | 25 | 28 | 28 | 25 |
Feels °C | 30 | 34 | 33 | 31 | 32 | 22 | 24 | 24 | 25 | 29 | 30 | 28 | 31 | 31 | 31 | 31 | 31 | 30 | 31 | 31 | 30 |
Swell 1 Height (m) Direction Period (s) | S 9 | S 9 | SSE 10 | E 18 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 8 | SSE 7 | SSE 7 | SSE 7 | S 7 | ESE 9 | ESE 9 | ESE 5 | SE 9 | SSW 10 | ESE 9 |
| kJ | 327 | 539 | 1153 | 6 | 785 | 243 | 188 | 184 | 171 | 123 | 145 | 94 | 52 | 40 | 23 | 47 | 59 | 34 | 174 | 19 | 313 |
Swell 2 Height (m) Direction Period (s) | SE 8 | SE 8 | — | — | E 18 | E 16 | E 16 | E 15 | ESE 11 | E 15 | E 14 | SE 10 | SE 10 | SE 10 | ESE 10 | S 7 | S 7 | SE 9 | SSW 8 | E 12 | SSW 9 |
| kJ | 182 | 210 | — | — | 6 | 5 | 5 | 4 | 12 | 17 | 15 | 24 | 24 | 25 | 35 | 15 | 15 | 83 | 13 | 12 | 16 |
Swell 3 Height (m) Direction Period (s) | — | ESE 10 | — | — | — | — | — | E 18 | E 15 | E 10 | E 14 | E 14 | E 13 | E 14 | E 14 | E 13 | E 13 | S 7 | E 13 | E 16 | E 13 |
| kJ | — | 39 | — | — | — | — | — | 6 | 17 | 7 | 60 | 36 | 31 | 32 | 35 | 31 | 31 | 8 | 13 | 5 | 50 |
Wind waves Height (m) Direction Period (s) | NE 3 | — | SSE 10 | SSE 9 | — | NNE 6 | NNE 5 | NNE 4 | NE 3 | NNE 3 | NE 4 | NE 4 | NE 3 | NE 3 | — | — | ESE 4 | — | ESE 9 | SE 8 | — |
| kJ | 3 | — | 1382 | 1414 | — | 74 | 39 | 13 | 3 | 4 | 11 | 4 | 3 | 2 | — | — | 7 | — | 328 | 295 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 22 | 0 | 0 | 245 | 11 | 14 | 14 | 0 | 0 | 0 | 0 | 0 | 0 | 41 | 0 | 43 | 19 | 19 | 19 | 19 | 0 |
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.
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