Surf Forecasts:
Amatu surf forecast from 24 Aug 2026:
- Best quality surf: Friday 28 Aug, 12AM (local time) - 2.5ft (0.8m), 13s period, E swell with glassy winds.
- Most powerful swell: Tuesday 25 Aug, 6AM (local time) - 6.5ft (2.0m), 13s period, S swell with 1,400 kJ wave energy.
- Next surfable swell (1★+): Thursday 27 Aug, 9PM (local time) - 2.5ft (0.8m), 13s period with E swell.
Best Forecast Surf Conditions for Amatu this week:
The surf forecast for Amatu over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Aug 27) at 9PM. The primary swell is predicted to be 0.8m and 13s period with a secondary swell of 0.8m and 6s. Another secondary swell of 1.3m and 6s is also forecast. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Amatu in the next 16 days are 2.0m 13s and forecast to arrive on Tuesday (Aug 25) at 6AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 4s period and expected on Saturday (Aug 29) at 12PM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 9PM (Thu 27th Aug) | 2.5ft (0.8m) 13s |
| Best Surf | 12AM (Fri 28th Aug) | 2.5ft (0.8m) 13s |
| Most Powerful | 6AM (Tue 25th Aug) | 6.5ft (2.0m) 13s |
Table - best surf conditions forecast for Amatu over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s cookin’ for Amatu over the next couple of weeks.
Right off the bat, we’ve got a bit of a dry spell. The first proper surf that’s worth paddling out for doesn’t show up until Friday morning, the 28th of August. Before that, Tuesday through Thursday is mostly a write-off – messy winds, poor conditions, and swell that’s just not cooperating. So, settle in for a few days of watching the tide come in and out.
Now, Friday morning the 28th is where it finally gets interesting. We’ve got a tiny but clean 3ft swell rolling in from the east, with a period of 12 seconds. The real kicker here is the wind – it’s glassy. That’s right, absolute glass. The combined energy is a modest 290, but for a beginner-friendly spot that’s inconsistent, this is a rare moment of calm. The water temp is sitting about average for this time of year, so no wetsuit drama. If you’re keen for a quiet, easy paddle and a few clean little waves, this is your window. Just keep in mind it’s inconsistent, so bring your patience.
The rest of that weekend and into the start of September is pretty flat and ordinary. Small, weak swells in the 2ft range with cross-off winds keep things clean, but the energy is low (around 123 to 145) and the waves are just too small to get excited about. It’s surfable, but you’ll be working hard for nothing special.
Moving into the second week, we get a bit of a pulse around the 4th of September. Friday morning the 4th sees a 4ft SSW swell, but with a very short period of just 6 seconds. That’s straight-up windswell, and it’s going to be a bit lumpy and weak. The wind turns offshore from the north, so it’s clean, but the wave quality is going to be pretty average. Still, it’s a surf.
Saturday morning the 5th is a repeat of that – clean conditions with a light offshore from the north, but the swell is still short-period (7 seconds) and only 4ft. It’s a surf, but nothing to write home about.
Now, here’s the big one. Sunday the 6th of September, the forecast shows a massive 10ft SSE groundswell hitting. This thing has a long period of 14 seconds, and the combined energy is a whopping 3285. That’s serious power. But – and this is a big but – it’s too big for Amatu. The wind is a moderate cross-onshore, and the setup is just going to be a washing machine. This is going to be a total mess, not a surf. Don’t even think about it.
The real standout, if you’re an experienced surfer, comes on Tuesday afternoon the 8th of September. The swell has dropped to a still-chunky 8ft from the south, period is a moderate 10 seconds, and the combined energy is 1187. But the wind flips around to a light offshore from the northwest, and the conditions are clean. For a spot that’s usually a beginner zone, this is a big, powerful, clean swell. It’s going to be a heavy, hollow wave, and it’s strictly for experts. The crowds will be possible, but given the size, most punters will be on the beach. This is the one to circle on the calendar.
So, to sum it up: the best bet for a casual, clean surf is Friday morning the 28th of August. The big dog for experienced surfers is Tuesday afternoon the 8th of September. Everything else is either flat, messy, or way too big.
Stay safe out there.
Rusty
Short Range ForecastModerate rain (total 14mm), heaviest on Thu afternoon. Warm (max 30°C on Wed morning, min 23°C on Thu night). Winds decreasing (fresh winds from the SW on Wed night, calm by Thu night). | Days 4-6 Weather SummaryLight rain (total 9mm), mostly falling on Sat afternoon. Warm (max 28°C on Sat morning, min 23°C on Sat night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | |||||||||||||||
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 13 | S 12 | S 11 | SSW 12 | SSW 12 | SW 6 | E 14 | S 11 | E 13 | E 12 | E 12 | E 12 | E 12 | E 11 | E 11 | E 11 | E 12 | E 12 | E 11 | E 11 | ESE 12 |
Wave Graph | |||||||||||||||||||||
1335 | 895 | 326 | 233 | 199 | 160 | 102 | 141 | 212 | 193 | 139 | 137 | 98 | 93 | 88 | 63 | 103 | 99 | 89 | 88 | 83 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross | cross | cross-on | cross | cross | cross | glassy | glassy | cross-on | cross-off | cross-off | cross-off | off | cross-off | cross | cross-off | cross-off | cross | cross-off |
High Tide | 4:29PM1.37m | 2:49AM1.38m | 4:45PM1.42m | 3:29AM1.45m | 5:02PM1.47m | 4:06AM1.52m | 5:20PM1.51m | 4:43AM1.55m | 5:39PM1.53m | 5:21AM1.55m | 6:00PM1.55m | 6:02AM1.52m | 6:21PM1.55m | ||||||||
Low Tide | 9:17AM0.28m | 9:43PM0.95m | 9:49AM0.22m | 10:08PM0.85m | 10:19AM0.19m | 10:33PM0.75m | 10:47AM0.20m | 11:00PM0.64m | 11:15AM0.24m | 11:29PM0.54m | 11:43AM0.32m | 00:01AM0.45m | 12:11PM0.44m | 00:35AM0.39m | |||||||
5:05 | — | — | 5:05 | — | — | 5:07 | — | — | 5:07 | — | — | 5:07 | — | — | 5:09 | — | — | 5:09 | — | — | |
— | 6:15 | — | — | 6:15 | — | — | 6:14 | — | — | 6:12 | — | — | 6:10 | — | — | 6:09 | — | — | 6:07 | — | |
mm | — | — | — | — | — | — | 1 | 5 | 8 | 2 | — | — | 1 | 5 | 1 | — | — | — | — | — | 1 |
Temp °C | 29 | 29 | 26 | 30 | 29 | 27 | 30 | 29 | 25 | 27 | 27 | 25 | 28 | 27 | 25 | 27 | 26 | 24 | 26 | 26 | 24 |
Feels °C | 30 | 29 | 26 | 32 | 30 | 28 | 31 | 31 | 28 | 31 | 29 | 28 | 31 | 31 | 29 | 30 | 28 | 27 | 28 | 28 | 26 |
Swell 1 Height (m) Direction Period (s) | S 13 | S 12 | S 11 | SSW 12 | SSE 9 | SSE 9 | SSE 8 | S 11 | S 10 | E 12 | E 12 | SSW 7 | E 12 | E 11 | E 11 | E 11 | E 12 | E 12 | E 11 | E 11 | E 6 |
1335 | 895 | 326 | 233 | 121 | 94 | 73 | 141 | 192 | 193 | 139 | 88 | 98 | 93 | 88 | 63 | 103 | 99 | 89 | 88 | 44 | |
Swell 2 Height (m) Direction Period (s) | E 14 | E 13 | SSW 12 | SSE 9 | SSW 12 | E 12 | SW 11 | E 13 | E 13 | S 9 | S 8 | E 12 | S 8 | SSW 7 | SE 10 | SE 10 | SE 10 | SE 10 | NE 7 | NE 8 | E 11 |
311 | 225 | 208 | 121 | 199 | 98 | 92 | 128 | 212 | 55 | 33 | 137 | 28 | 26 | 27 | 26 | 27 | 28 | 19 | 20 | 65 | |
Swell 3 Height (m) Direction Period (s) | — | — | E 13 | E 12 | E 12 | S 12 | E 14 | SW 10 | SW 10 | SE 9 | SSE 10 | SSE 10 | SW 6 | SSE 11 | SSW 8 | SSW 7 | SSW 7 | SSW 8 | SE 9 | SE 9 | ESE 12 |
— | — | 215 | 148 | 138 | 72 | 102 | 64 | 36 | 23 | 37 | 38 | 14 | 47 | 20 | 17 | 11 | 12 | 31 | 31 | 83 | |
Wind waves Height (m) Direction Period (s) | SW 4 | SW 4 | SW 5 | SW 5 | SW 5 | SW 6 | SW 6 | SW 6 | SW 6 | SW 6 | SW 6 | WSW 6 | ENE 3 | ENE 5 | E 5 | E 5 | E 5 | E 5 | ESE 6 | ESE 6 | S 4 |
24 | 36 | 71 | 43 | 49 | 160 | 75 | 46 | 77 | 102 | 111 | 75 | 8 | 30 | 32 | 23 | 22 | 42 | 50 | 50 | 4 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 75 | 231 | 30 | 24 | 582 | 30 | 30 | 14 | 0 | 0 | 30 | 0 | 0 | 0 | 0 | 0 | 43 | 0 | 0 | 40 | 0 |
Best forecast wave conditions in Chiba | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
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Information about the Amatu Surf forecast
The above surf forecast table for Amatu provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Amatu can be found by selecting the local surf guide option on the grey menu. Our Amatu 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 (Amatu) 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 Amatu 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.
Amatu is 9 km (6 miles) from Kawaguchi. If you plan a holiday in Chiba, look for hotels and other accommodation in Kawaguchi. Kawaguchi has rooms for a wide range of budgets as well as car hire and transport links.











