
Surf Forecasts:
Asakawa surf forecast from 13 Sep 2026:
- Best quality surf: Sunday 20 Sep, 6PM (local time) - 13ft (4.0m), 14s period, SE swell with cross-offshore winds.
- Most powerful swell: Monday 21 Sep, 9AM (local time) - 16ft (5.0m), 15s period, SSE swell with 11,139 kJ wave energy.
- Next surfable swell (1★+): Monday 14 Sep, 9AM (local time) - 3.5ft (1.0m), 8s 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 Monday (Sep 14) at 9AM. The primary swell is predicted to be 1.0m and 8s period with a secondary swell of 0.2m and 13s. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Asakawa in the next 16 days are 5.0m 15s and forecast to arrive on Monday (Sep 21) at 9AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 5s period and expected on Sunday (Sep 20) at 6PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9AM (Mon 14th Sep) | 3.5ft (1.0m) 8s |
| Best Surf | 6PM (Sun 20th Sep) | 13ft (4.0m) 14s |
| Most Powerful | 9AM (Mon 21st Sep) | 16ft (5.0m) 15s |
Table - best surf conditions forecast for Asakawa over the next 16 days.
The Lowdown
Alright, let me tell you what's cooking at Asakawa over the next couple of weeks. Things are looking pretty flat and ordinary to kick things off, but there's some serious size coming down the line if you're willing to wait for it.
The start of the period is pretty quiet. Monday the 14th has a tiny 3ft swell from the SE, with a short 8-second period and weak energy (148). The morning is glassy, which is nice, but the afternoon gets a bit of an onshore breeze, so it's nothing to get excited about. Tuesday morning the 15th looks a little better, with the swell picking up to 5ft from the SE and a slightly longer 9-second period, and it’s dead calm—glassy conditions. That's your best early window, but the water temp is sitting at 82°, which is about average for this time of year. The afternoon goes a bit sloppy again.
Wednesday and Thursday (16th and 17th) drop back down, with weak energy and cross-off or cross winds. Just surfable, not worth rushing for.
Now, Friday the 18th gets a bit interesting. The morning sees a jump to 8ft from the east, with an 8-second period and moderate energy (1032). It’s a bit of a messy cross-shore wind, so it's not clean, but there's some push there. That swell is already building toward the real event.
The standout window arrives on Saturday the 19th. This is the one to circle. Saturday morning brings a solid 10ft swell from the ESE, with a very long 15-second period. The combined energy is enormous (4398), and with a light cross-offshore breeze from the NNE, conditions are clean. This is excellent for experienced surfers—this is groundswell, and it’s big. At over 8ft, this is expert territory. The long period means it’ll be powerful, with proper gaps between sets, making it easier to get out the back. Asakawa is a point break, and the swell direction (ESE) lines up well with the optimum SE direction, so it should wrap in nicely. The morning is the pick. Saturday afternoon stays big and clean but the period drops slightly to 14 seconds. Crowds are possible here, so get in early.
Sunday the 20th keeps the size up, with 12-13ft SE swell and 14-second periods, but the wind picks up to a moderate breeze (12 mph) from the NNE. It’s still cross-offshore and clean, so it’s rideable, but the wind makes it a bit more challenging. This is still for experienced surfers.
Monday the 21st goes nuclear. The morning shows a massive 16ft swell from the SSE with a 15-second period and extreme energy (11139). The wind is a moderate cross-offshore breeze, keeping it clean, but this is huge. Only the most experienced should even think about it. The afternoon gets even bigger, 20ft from the SE, but the wind swings onshore and gets lumpy, so quality drops.
Tuesday the 22nd sees the swell drop back to 10ft from the ESE, with a 12-second period and strong energy (2386). The morning has a near gale offshore wind (31 mph), which is clean but incredibly hard to paddle into—only for the elite. The afternoon settles down nicely: 6ft from the ESE, 11-second period, moderate offshore wind, and clean. That’s a much more manageable session for strong intermediates.
After that, it fades fast. Wednesday the 23rd through Friday the 26th are tiny, with minimal energy and poor conditions. You’re looking at a solid 3-4 day gap of flatness.
Sunday the 27th brings a new pulse: 6ft from the SSE with a long 14-second period and moderate energy (1866), but the wind is onshore and choppy in the afternoon. The morning is light cross-shore, so it’s possible.
The real finale is Monday the 28th. Monday morning delivers a 10ft swell from the south, with a very long 16-second period and extreme energy (5371). It’s glassy, with a slight air from the east. This is excellent for experienced surfers. The afternoon is even better: still 10ft, 16-second period, glassy, with energy jumping to 7318. That’s exceptional surf. This is a proper south swell, and with that period, it’ll have plenty of power. Tuesday the 29th holds at 13ft from the south with the same long period, but the wind picks up to a moderate cross-offshore breeze, keeping it clean but making it a bit more of a handful.
Overall, your two best windows are Saturday the 19th morning and Monday the 28th. Saturday is a cleaner, more manageable big swell for experts, while the 28th is the absolute standout for power and conditions. Don’t sleep on the Tuesday 22nd afternoon if you want something a bit smaller.
Rusty.
Short Range ForecastHeavy rain (total 32mm), heaviest during Tue afternoon. Warm (max 29°C on Mon morning, min 22°C on Wed night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 22mm), heaviest during Thu night. Warm (max 28°C on Sat afternoon, min 23°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | |||||||||||||||
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 8 | SE 8 | SE 10 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | ESE 9 | SE 9 | SE 8 | ESE 8 | E 8 | ESE 9 | ESE 15 | ESE 15 | ESE 14 | SE 14 | SE 14 | SE 14 | SSE 14 |
Wave Graph | |||||||||||||||||||||
132 | 138 | 296 | 300 | 237 | 178 | 112 | 110 | 99 | 77 | 74 | 207 | 686 | 336 | 1655 | 4392 | 4005 | 4421 | 5497 | 5842 | 7231 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | on | glassy | glassy | on | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross-on | cross | cross-on | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 7:22PM1.79m | 8:09AM1.67m | 7:43PM1.73m | 8:48AM1.54m | 8:04PM1.66m | 9:32AM1.40m | 8:24PM1.57m | 10:38AM1.28m | 8:45PM1.47m | 1:48PM1.23m | 9:10PM1.37m | 3:50PM1.33m | 11:43PM1.27m | ||||||||
Low Tide | 1:24PM0.57m | 1:46AM0.29m | 1:50PM0.72m | 2:19AM0.34m | 2:13PM0.87m | 2:54AM0.42m | 2:34PM1.00m | 3:36AM0.53m | 2:53PM1.12m | 4:39AM0.64m | 2:46PM1.23m | 6:31AM0.69m | 8:58PM1.25m | ||||||||
5:43 | — | — | 5:45 | — | — | 5:45 | — | — | 5:46 | — | — | 5:47 | — | — | 5:47 | — | — | 5:48 | — | — | |
— | 6:10 | — | — | 6:09 | — | — | 6:07 | — | — | 6:07 | — | — | 6:06 | — | — | 6:04 | — | — | 6:02 | — | |
mm | — | 1 | 6 | 3 | 6 | 7 | 4 | 4 | 1 | 1 | 7 | 13 | — | 1 | — | — | — | — | — | — | 1 |
Temp °C | 29 | 28 | 24 | 27 | 27 | 24 | 26 | 25 | 23 | 26 | 25 | 24 | 25 | 26 | 24 | 27 | 28 | 25 | 25 | 27 | 25 |
Feels °C | 32 | 30 | 28 | 31 | 31 | 27 | 29 | 28 | 25 | 28 | 28 | 26 | 28 | 29 | 27 | 29 | 29 | 27 | 25 | 28 | 27 |
Swell 1 Height (m) Direction Period (s) | SE 8 | SE 8 | SE 10 | SE 9 | SE 9 | SE 9 | SE 9 | SE 9 | ESE 9 | SE 9 | SE 8 | ESE 8 | ESE 8 | ESE 9 | ESE 15 | ESE 15 | ESE 14 | SE 14 | SE 14 | SE 14 | SSE 14 |
132 | 138 | 296 | 300 | 237 | 178 | 112 | 110 | 99 | 77 | 74 | 207 | 330 | 336 | 1655 | 4392 | 4005 | 4421 | 5497 | 5842 | 7231 | |
Swell 2 Height (m) Direction Period (s) | E 13 | E 12 | E 12 | S 7 | E 13 | E 13 | E 12 | S 7 | E 13 | E 12 | E 12 | E 12 | SE 19 | ESE 17 | ESE 9 | S 9 | S 9 | — | — | E 10 | ESE 10 |
13 | 12 | 12 | 1 | 14 | 12 | 3 | 1 | 3 | 3 | 3 | 3 | 14 | 116 | 275 | 6 | 6 | — | — | 633 | 540 | |
Swell 3 Height (m) Direction Period (s) | S 6 | S 7 | S 7 | E 15 | S 6 | S 7 | E 14 | S 7 | S 7 | S 7 | S 7 | — | S 11 | S 10 | S 10 | — | S 9 | — | — | — | — |
3 | 1 | 1 | 17 | 1 | 1 | 4 | 1 | 1 | 1 | 1 | — | 2 | 2 | 7 | — | 6 | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | NE 3 | NE 4 | NNE 3 | NNE 4 | NE 3 | — | E 8 | NNE 3 | E 9 | NNE 4 | NNE 4 | N 4 | NNE 5 | NNE 5 | NNE 4 |
— | — | — | — | — | — | 2 | 11 | 4 | 8 | 5 | — | 686 | 3 | 642 | 27 | 22 | 24 | 54 | 46 | 39 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 11 | 0 | 0 | 11 | 0 | 0 | 0 | 0 | 0 | 43 | 43 | 19 | 19 | 57 | 0 | 43 | 22 | 22 | 43 | 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.










