Surf Forecasts:
Big Ben surf forecast from 17 Aug 2026:
- Best quality surf: Monday 24 Aug, 3PM (local time) - 10ft (3.0m), 16s period, SSE swell with cross-onshore winds.
- Most powerful swell: Tuesday 25 Aug, 3AM (local time) - 10ft (3.0m), 16s period, SSE swell with 5,020 kJ wave energy.
- Next surfable swell (1★+): Thursday 20 Aug, 3AM (local time) - 1.5ft (0.4m), 10s period with SE swell.
Best Forecast Surf Conditions for Big Ben this week:
The surf forecast for Big Ben over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Thursday (Aug 20) at 3AM. The primary swell is predicted to be 0.4m and 10s period with a secondary swell of 0.6m and 6s. Another secondary swell of 0.4m and 9s is also forecast. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Big Ben in the next 16 days are 3.0m 16s and forecast to arrive on Tuesday (Aug 25) at 3AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 10s period and expected on Tuesday (Aug 25) at 6AM.
| Wave Type | Time (JST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 3AM (Thu 20th Aug) | 1.5ft (0.4m) 10s |
| Best Surf | 3PM (Mon 24th Aug) | 10ft (3.0m) 16s |
| Most Powerful | 3AM (Tue 25th Aug) | 10ft (3.0m) 16s |
Table - best surf conditions forecast for Big Ben over the next 16 days.
The Lowdown
Alright surfers, Rusty here. Let's get into it. It's a bit of a slow start, so bear with me.
For the first part of this forecast, the ocean's pretty quiet. From the 18th through the 22nd, there's nothing doing at Big Ben (South West). We've got weak, short-period swell and onshore winds messing things up. It's small and jumbled, not worth your time. The combined wave energy is weak, reading 156, 144, 104, and similar numbers. It's a flat patch, a good chance to get things sorted.
We get a little hint of life on the 23rd. Sunday morning sees a slight bump in energy to 294, but the swell is still small, around 3ft from the E with a light cross-shore wind. It's still only marginal, so not a real goer. There's also a storm risk hanging around.
The real story starts on Monday, the 24th. A proper groundswell starts to roll in. We're talking 8ft on Monday morning from the SSE with a long 17-second period. The energy jumps to 3520. By the afternoon, it's 10ft and the energy is climbing to 4054. But here's the catch – while the wind is light, this swell is forecast to be too big for this break. This is pushing it into expert territory, and for a mellow spot like Big Ben, that's a lot of power.
Tuesday, the 25th, is the peak. The morning sees a solid 10ft of SSE swell with a 16-second period and light, glassy SE winds. The energy is massive, reading 4847. This is the standout, the best chance we have for a proper session. It's still big, well over 8ft, so it's only for experts, but it will be powerful and clean early. The afternoon backs off slightly to 10ft with a bit more breeze, but still strong.
From Wednesday the 26th through to the 29th, the swell drops but stays relevant. We're looking at 8ft dropping to around 4-5ft, with periods around 13-14 seconds. However, the wind becomes more of a problem, turning cross-onshore and making things choppy. The energy is strong, in the 1500-3100 range, but the quality drops off. It's a bit of a churned-up mess. By the 28th and 29th, the wind is howling from the SE at up to 19 mph, making it lumpy and pretty much unsurfable at this spot.
The end of the window, from the 30th through to the 2nd of September, is another mixed bag. The 31st of August sees another huge pulse, with 13ft to 16ft of SE swell predicted, with a massive energy reading of 9229. Again, the wind is light, but the size is just too much for this break. It's not a realistic option for most. After that, it fades through the 1st and 2nd, with decreasing 10ft to 7ft swell, but winds stay onshore and the quality drops off.
There's a lot of power in this forecast, but not a lot of quality for a break like Big Ben. The best bet is the early morning of the 25th, if you're an expert and can handle some serious juice. Beyond that, you're looking at washed-out conditions or waves that are simply too big for the spot. Take care out there.
Rusty.
Short Range ForecastMostly dry. Warm (max 28°C on Tue morning, min 24°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryHeavy rain (total 20mm), heaviest during Sat morning. Warm (max 28°C on Fri morning, min 25°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | |||||||||||||||
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) | ESE 8 | E 9 | E 9 | E 9 | SE 10 | E 9 | SE 11 | SE 11 | SE 11 | SE 11 | ESE 9 | E 10 | E 9 | E 10 | E 10 | E 10 | SSE 13 | SSE 18 | SSE 17 | SSE 16 | SSE 16 |
Wave Graph | |||||||||||||||||||||
107 | 73 | 54 | 39 | 49 | 39 | 59 | 57 | 57 | 58 | 90 | 92 | 111 | 149 | 194 | 186 | 116 | 436 | 3269 | 3860 | 4889 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | cross-on | on | on | on | on | glassy | cross-on | cross-on | cross | cross | cross-on | cross | cross | cross-on | cross | cross | cross-on | glassy |
High Tide | 7:24PM1.50m | 8:20AM1.27m | 7:46PM1.47m | 9:31AM1.15m | 8:09PM1.44m | 8:37PM1.39m | 9:26PM1.33m | 4:10PM1.33m | 00:01AM1.29m | 4:16PM1.41m | 1:46AM1.34m | ||||||||||
Low Tide | 1:17PM0.66m | 2:01AM0.49m | 1:39PM0.82m | 2:52AM0.50m | 1:53PM0.97m | 4:00AM0.52m | 5:40AM0.51m | 7:19AM0.44m | 8:35PM1.23m | 8:26AM0.35m | 9:17PM1.13m | ||||||||||
5:00 | — | — | 5:01 | — | — | 5:01 | — | — | 5:03 | — | — | 5:03 | — | — | 5:03 | — | — | 5:05 | — | — | |
— | 6:24 | — | — | 6:23 | — | — | 6:22 | — | — | 6:22 | — | — | 6:20 | — | — | 6:19 | — | — | 6:17 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | 3 | 3 | 7 | 2 | 2 | 2 | 1 | — | — |
Temp °C | 28 | 27 | 25 | 28 | 28 | 25 | 27 | 27 | 25 | 28 | 28 | 26 | 28 | 28 | 26 | 28 | 28 | 26 | 27 | 28 | 26 |
Feels °C | 31 | 29 | 28 | 31 | 31 | 28 | 30 | 29 | 28 | 30 | 30 | 30 | 30 | 30 | 30 | 31 | 31 | 30 | 30 | 31 | 29 |
Swell 1 Height (m) Direction Period (s) | ESE 8 | E 9 | SE 6 | SE 6 | SE 6 | SE 6 | ESE 5 | SE 5 | E 8 | E 7 | ESE 9 | E 10 | E 9 | E 10 | E 10 | E 10 | E 9 | SSE 16 | SSE 17 | SSE 16 | SSE 16 |
107 | 73 | 33 | 29 | 28 | 26 | 19 | 13 | 33 | 24 | 90 | 92 | 111 | 149 | 194 | 186 | 110 | 425 | 3269 | 3860 | 4889 | |
Swell 2 Height (m) Direction Period (s) | SE 10 | SE 7 | E 9 | E 9 | E 9 | E 9 | SE 11 | SE 11 | SE 11 | SSW 9 | SSW 9 | SSW 10 | SSW 9 | SSW 9 | SSW 9 | SW 9 | SSE 13 | SSE 18 | E 12 | E 12 | ESE 11 |
36 | 35 | 54 | 39 | 39 | 39 | 59 | 57 | 57 | 45 | 44 | 55 | 58 | 55 | 56 | 41 | 116 | 436 | 216 | 177 | 123 | |
Swell 3 Height (m) Direction Period (s) | SSW 8 | SE 10 | SE 10 | SE 10 | SE 10 | SE 10 | ENE 9 | ENE 9 | SSW 8 | SE 11 | SE 11 | SE 11 | S 5 | SE 10 | SE 11 | SE 14 | ESE 12 | E 9 | SW 8 | E 15 | E 14 |
13 | 36 | 36 | 36 | 49 | 37 | 26 | 26 | 23 | 58 | 30 | 29 | 11 | 28 | 29 | 53 | 82 | 81 | 35 | 17 | 58 | |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | ESE 7 | — | SSE 5 | S 4 | S 4 | S 4 | SSW 4 | SSW 9 | SW 8 | — | — | SW 10 |
— | — | — | — | — | — | — | — | — | 48 | — | 18 | 14 | 14 | 12 | 14 | 70 | 72 | — | — | 77 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 30 | 30 | 30 | 22 | 30 | 30 | 30 | 30 | 0 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 30 | 35 |
Best forecast wave conditions in Chiba | |||||||||||||||||||||
Best forecast wave conditions in Japan | |||||||||||||||||||||
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Information about the Big Ben Surf forecast
The above surf forecast table for Big Ben provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Big Ben can be found by selecting the local surf guide option on the grey menu. Our Big Ben 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 (Big Ben) 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 Big Ben 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.
Big Ben is 3 km (2 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.











