
Surf Forecasts:
Big Bay surf forecast from 8 Sep 2026:
- Best quality surf: Saturday 12 Sep, 11PM (local time) - 7.5ft (2.3m), 15s period, SW swell with offshore winds.
- Most powerful swell: Tuesday 15 Sep, 8PM (local time) - 8ft (2.5m), 18s period, WSW swell with 4,403 kJ wave energy.
- Next surfable swell (1★+): Tuesday 8 Sep, 11PM (local time) - 3ft (0.9m), 11s period with SW swell.
Best Forecast Surf Conditions for Big Bay this week:
The surf forecast for Big Bay over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Tuesday (Sep 08) at 11PM. The primary swell is predicted to be 0.9m and 11s period with a secondary swell of 0.6m and 15s. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Big Bay in the next 16 days are 2.5m 18s and forecast to arrive on Tuesday (Sep 15) at 8PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 5s period and expected on Friday (Sep 11) at 8AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Tue 8th Sep) | 3ft (0.9m) 11s |
| Best Surf | 11PM (Sat 12th Sep) | 7.5ft (2.3m) 15s |
| Most Powerful | 8PM (Tue 15th Sep) | 8ft (2.5m) 18s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright folks, Rusty here with the long-range look for the next couple of weeks. Let's see what Mother Nature’s got cookin'.
The forecast starts off pretty quiet for the first couple of days. We've got some small waves rolling in on Tuesday the 8th and Wednesday the 9th, with clean conditions, but there just isn't enough push to get overly excited about. The combined swell energy is sitting around 306 (weak to moderate) to 339, which is barely a ripple for this exposed spot. The water temp is 53°F, which is 7°F colder than normal, so you'll definitely want a thick wetsuit if you're paddling out at Big Bay.
Now, Thursday the 10th is where things start to get interesting. That morning, we see a solid jump to 8ft of SW swell, and the energy climbs to 2215 which is strong. This is proper groundswell with a 15-second period, and with the cross-off wind, it’s gonna be clean. This is for the experienced crew only; this is big, powerful juice.
The rest of that week and into Saturday the 12th holds fairly consistent 5ft to 7ft swell from the SW, but the wind is a bit stronger and more cross-off, keeping it manageable but not glassy. The combined energy stays strong – 1088 to 3454 – so there's plenty of water moving.
We hit a bit of a lull on Monday the 14th and Tuesday the 15th with onshore winds gusting up to 19 mph. The wave heights drop, and conditions get choppy and lumpy. This is a definite write-off. Not worth paddling out.
The standout window really opens up on Wednesday the 16th. We get a pulse of 12ft of WSW swell, and the energy hits a massive 4395. The wind is cross-off and clean. This is expert territory – big, powerful, and potentially dangerous if you're not on your game.
But if you can hold out a little longer, the absolute pick of the forecast is Monday the 21st of September. The morning session looks absolutely epic. We're looking at 12ft of solid SW swell with a 17-second period. The combined energy is a monstrous 6463, and the wind is light offshore from the SE. That's the recipe for perfection for the big-wave chargers.
Following that, Tuesday the 22nd and Wednesday the 23rd see the swell size remain, but the wind swings onshore, making things messy and choppy again.
So to wrap it up: the early stuff is small and clean but weak. The real deal starts on the 10th for the experienced, and the absolute epicenter is the morning of Monday the 21st. Mark it on your calendar, but remember it’s a long way off – forecasts can shift. Still, that one has all the makings of something special.
Rusty, signing off.
Short Range ForecastMostly dry. Warm (max 25°C on Tue afternoon, min 14°C on Wed night). Wind will be generally light. | Days 5-7 Weather SummaryLight rain (total 6mm), mostly falling on Sun night. Warm (max 22°C on Sun afternoon, min 15°C on Fri night). Wind will be generally light. | |||||||||||||||||||
Tue 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | ||||||||||||||
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) | WSW 12 | SW 11 | WSW 13 | WSW 13 | WSW 12 | SW 15 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | S 8 | SW 14 | SW 16 | SW 14 | SW 14 | SW 14 | SW 13 | SW 12 | SW 12 | NW 8 |
Wave Graph | ||||||||||||||||||||
140 | 172 | 304 | 295 | 680 | 2215 | 1672 | 1383 | 967 | 710 | 491 | 1004 | 2445 | 1838 | 1233 | 1036 | 600 | 341 | 272 | 345 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | cross | cross | cross-off | on | cross-on | cross |
High Tide | 1:53AM1.44m | 2:15PM1.57m | 2:33AM1.51m | 2:51PM1.66m | 3:10AM1.55m | 3:25PM1.70m | 3:44AM1.55m | 3:58PM1.68m | 4:17AM1.52m | 4:29PM1.62m | 4:48AM1.45m | 4:59PM1.52m | ||||||||
Low Tide | 7:50PM0.20m | 8:04AM0.12m | 8:31PM0.08m | 8:41AM0.05m | 9:08PM0.01m | 9:15AM0.02m | 9:42PM-0.01m | 9:48AM0.03m | 10:15PM0.01m | 10:19AM0.08m | 10:45PM0.07m | 10:49AM0.16m | 11:15PM0.17m | |||||||
— | — | 6:54 | — | — | 6:52 | — | — | 6:50 | — | — | 6:50 | — | — | 6:48 | — | — | 6:47 | — | — | |
6:31 | — | — | 6:32 | — | — | 6:32 | — | — | 6:34 | — | — | 6:35 | — | — | 6:36 | — | — | 6:36 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | 3 | 5 | — |
Temp °C | 25 | 22 | 20 | 21 | 16 | 17 | 19 | 15 | 17 | 20 | 15 | 17 | 20 | 18 | 21 | 22 | 19 | 18 | 16 | 15 |
Feels °C | 22 | 21 | 19 | 19 | 15 | 16 | 17 | 11 | 14 | 18 | 11 | 15 | 19 | 17 | 20 | 20 | 16 | 18 | 13 | 12 |
Swell 1 Height (m) Direction Period (s) | WSW 12 | SW 11 | WSW 13 | WSW 13 | WSW 12 | SW 15 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | WSW 11 | SW 14 | SW 16 | SW 14 | SW 14 | SW 14 | SW 13 | SW 12 | SW 12 | SW 12 |
140 | 172 | 304 | 295 | 680 | 2215 | 1672 | 1383 | 967 | 710 | 307 | 1004 | 2445 | 1838 | 1233 | 1036 | 600 | 341 | 272 | 228 | |
Swell 2 Height (m) Direction Period (s) | SW 11 | WSW 14 | S 9 | W 11 | SW 17 | — | — | — | — | — | SW 14 | — | — | S 9 | S 9 | S 8 | S 8 | S 7 | SE 8 | SE 12 |
117 | 140 | 14 | 9 | 238 | — | — | — | — | — | 200 | — | — | 586 | 245 | 199 | 111 | 26 | 18 | 5 | |
Swell 3 Height (m) Direction Period (s) | S 10 | S 9 | W 11 | SE 10 | S 8 | — | — | — | — | — | SSW 10 | — | — | — | — | — | NNW 5 | — | — | — |
49 | 27 | 21 | 4 | 1 | — | — | — | — | — | 10 | — | — | — | — | — | 7 | — | — | — | |
Wind waves Height (m) Direction Period (s) | SSW 3 | S 3 | S 3 | S 4 | S 4 | — | S 4 | S 4 | S 7 | S 7 | S 8 | S 8 | S 9 | — | — | — | N 5 | NNW 5 | NW 6 | NW 8 |
2 | 3 | 3 | 18 | 10 | — | 18 | 28 | 233 | 378 | 491 | 822 | 1009 | — | — | — | 11 | 87 | 238 | 345 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 0 | 0 | 0 | 39 | 0 | 0 | 39 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 29 | 36 | 36 |
Best forecast wave conditions in Cape Town | ||||||||||||||||||||
Best forecast wave conditions in South Africa | ||||||||||||||||||||
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Information about the Big Bay Surf forecast
The above surf forecast table for Big Bay provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Big Bay can be found by selecting the local surf guide option on the grey menu. Our Big Bay 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 Bay) 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 Bay 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 Bay is 8 km (5 miles) from the very large city of Robben Island. If you plan a holiday in Cape Town, look for hotels and other accommodation in Robben Island. Robben Island has rooms for a wide range of budgets as well as cheap car hire and transport links.










