
Surf Forecasts:
Big Bay surf forecast from 11 Sep 2026:
- Best quality surf: Saturday 12 Sep, 8PM (local time) - 8ft (2.4m), 16s period, SW swell with offshore winds.
- Most powerful swell: Tuesday 15 Sep, 11PM (local time) - 10ft (3.0m), 15s period, WSW swell with 3,601 kJ wave energy.
- Next surfable swell (1★+): Saturday 12 Sep, 2AM (local time) - 4.5ft (1.3m), 12s period with WSW 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 Saturday (Sep 12) at 2AM. The primary swell is predicted to be 1.3m and 12s period with a secondary swell of 0.5m and 15s. Another secondary swell of 1.6m and 7s is also forecast. 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 3.0m 15s and forecast to arrive on Tuesday (Sep 15) at 11PM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 2.0m 6s period and expected on Monday (Sep 14) at 11AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Sat 12th Sep) | 4.5ft (1.3m) 12s |
| Best Surf | 8PM (Sat 12th Sep) | 8ft (2.4m) 16s |
| Most Powerful | 11PM (Tue 15th Sep) | 10ft (3.0m) 15s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s have a look at what’s on the table for Big Bay over the next couple of weeks.
Alright, so straight off the bat, the water is sitting at 56°, which is a solid 4° colder than what you’d expect for this time of year. That’s not just a little nippy, that’s seriously chilly for the season, so you’ll want the thickest rubber you’ve got.
The first few days (Friday the 11th through Sunday the 13th) are a bit of a mixed bag. The swell is building from the SW, but the winds are mainly cross-off from the SSE, which keeps things reasonably tidy. Friday morning sees a 6ft WSW swell with a period of 12 seconds, but the energy is moderate (1170) and the score is just ok. Saturday afternoon is a step up, with a 8ft SW swell at 16 seconds and the energy jumping to 2991, with offshore wind from the SE. That’s the start of something better. Sunday morning is the pick of this first block: 7ft SW, 14-second period, light offshore SE breeze at only 6 mph. That’s clean, lined-up, and the combined energy is a solid 2152. For an intermediate, that’s a very fair session, but at 7ft it’s starting to push into the ‘too big for beginners’ zone.
Then we hit a big gap of poor conditions. Monday the 14th through Tuesday the 16th is a write-off. Strong cross-onshore winds, lumpy and messy, with a few days of no real recommendation. The swell is all over the place and the wind is blowing it apart. Wednesday the 16th afternoon sees a return of clean surf with a 8ft SSW swell, 13 seconds, and combined energy of 3340 (strong). The wind is cross-off from the S at 16 mph, so it’s clean but a bit breezy. Still, that’s a long period groundswell and a powerful one.
Now, the real standout is the end of the first week and into the second. Friday the 18th is a beauty. Morning session has a 8ft SW swell (13 seconds) with a gentle offshore ESE breeze at 9 mph, and the energy is strong at 2867. The afternoon is even better: 8ft SW swell at 15 seconds, clean, offshore wind, energy at 3024. That is an excellent window for experienced surfers. The swell direction is directly from the SW, which is the optimum direction for this spot. Crowds are noted as “often”, so you’ll want to get out there early, but the quality is top shelf.
The following weekend is also strong. Saturday the 19th afternoon has a 10ft SW swell with an 18-second period, which is a very long period groundswell. The energy is 4675 – that’s very strong wave energy, and it will be cranking. That’s strictly for experts. A 10ft swell with that period will be heavy and powerful at a beach break. It might actually be more suited to a reef or point setup, but Big Bay is exposed and will be handling it. Sunday the 20th morning is glassy with a 8ft SW swell, 14 seconds, and energy at 2947. That’s possibly the best window: absolutely glassy, light winds, and solid, clean surf. For a surfer, that’s the one to circle – but again, 8ft is for the experienced crew. Beginners should stay well clear of both Saturday afternoon and Sunday morning.
After that, the surf settles down a bit into the second week. There’s a small window on Wednesday the 23rd afternoon with a 6ft SW swell, 16 seconds, SSE cross-off winds, and strong energy (2542) – a good session for intermediates. Thursday the 24th morning is also solid with a 7ft SW swell, 14 seconds, and a bit of a cross-off from the NE, which keeps it clean. The rest of the second week fades out with onshore winds and messier conditions, especially Friday the 25th with strong cross-onshore and rain. By Saturday the 26th, you’re looking at a moderate cross-shore chop and dropping quality.
Overall: the absolute best on offer is the Sunday the 20th morning session – glassy, 8ft SW swell, and clean. The next best is Friday the 18th afternoon, with 8ft and offshore wind. Both are for experienced surfers. The intermediate window is Sunday morning the 13th and maybe Wednesday the 23rd afternoon.
Rusty.
Short Range ForecastLight rain (total 8mm), mostly falling on Sun night. Warm (max 24°C on Sun afternoon, min 14°C on Fri morning). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 6mm), mostly falling on Tue night. Very mild (max 17°C on Wed afternoon, min 11°C on Wed night). Winds decreasing (fresh winds from the N on Mon morning, calm by Tue night). | ||||||||||||||||||||
Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | |||||||||||||||
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) | WSW 12 | WSW 12 | WSW 12 | SW 14 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 | SW 12 | NW 7 | SW 11 | SW 18 | WSW 16 | WSW 14 | WSW 13 | SSW 13 | SW 13 | SW 11 | SW 12 | SW 14 |
Wave Graph | |||||||||||||||||||||
830 | 680 | 407 | 1500 | 2711 | 2341 | 1945 | 1029 | 600 | 380 | 396 | 250 | 338 | 2836 | 3595 | 1811 | 1830 | 623 | 413 | 332 | 1733 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | cross-off | cross-off | off | off | off | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | glassy | cross-off | cross-off | off | cross-off | cross-off | off |
High Tide | 3:25PM1.70m | 3:44AM1.55m | 3:58PM1.68m | 4:17AM1.52m | 4:29PM1.62m | 4:48AM1.45m | 4:59PM1.52m | 5:18AM1.35m | 5:29PM1.40m | 5:49AM1.24m | 6:00PM1.27m | 6:24AM1.13m | 6:36PM1.13m | ||||||||
Low Tide | 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 | 11:18AM0.26m | 11:44PM0.28m | 11:48AM0.38m | 00:15AM0.41m | 12:20PM0.51m | 00:53AM0.53m | |||||||
6:50 | — | — | 6:50 | — | — | 6:48 | — | — | 6:47 | — | — | 6:46 | — | — | 6:43 | — | — | 6:43 | — | — | |
— | 6:34 | — | — | 6:35 | — | — | 6:36 | — | — | 6:36 | — | — | 6:37 | — | — | 6:37 | — | — | 6:37 | — | |
mm | — | — | — | — | — | — | — | 1 | 7 | — | — | 2 | — | — | 4 | — | — | — | — | — | — |
Temp °C | 18 | 20 | 16 | 19 | 18 | 16 | 20 | 24 | 17 | 16 | 16 | 15 | 16 | 16 | 15 | 15 | 17 | 15 | 14 | 18 | 15 |
Feels °C | 15 | 17 | 13 | 16 | 14 | 13 | 19 | 22 | 17 | 10 | 10 | 11 | 11 | 10 | 11 | 9 | 12 | 12 | 10 | 15 | 11 |
Swell 1 Height (m) Direction Period (s) | WSW 12 | WSW 12 | WSW 12 | SW 14 | SW 16 | SW 15 | SW 14 | SW 14 | SW 13 | SW 12 | SW 12 | SW 11 | WSW 7 | WSW 16 | WSW 14 | WSW 13 | WSW 13 | SW 13 | SW 11 | SW 12 | SW 14 |
830 | 680 | 407 | 1500 | 2711 | 2341 | 1945 | 1029 | 600 | 380 | 314 | 250 | 108 | 2836 | 3595 | 1811 | 711 | 623 | 413 | 332 | 1733 | |
Swell 2 Height (m) Direction Period (s) | — | — | SW 15 | — | — | S 7 | SSE 8 | S 8 | S 7 | S 13 | SE 13 | WSW 5 | SW 11 | W 8 | NNW 6 | SW 14 | W 13 | WSW 12 | W 12 | WSW 12 | SW 20 |
— | — | 107 | — | — | 120 | 207 | 95 | 39 | 3 | 7 | 13 | 174 | 324 | 15 | 506 | 799 | 454 | 294 | 186 | 97 | |
Swell 3 Height (m) Direction Period (s) | — | — | S 10 | — | — | — | — | SSE 12 | — | SE 13 | — | SW 18 | SW 18 | — | — | — | — | — | — | SW 16 | W 11 |
— | — | 50 | — | — | — | — | 13 | — | 6 | — | 13 | 338 | — | — | — | — | — | — | 155 | 21 | |
Wind waves Height (m) Direction Period (s) | S 7 | S 7 | S 7 | S 8 | SSE 8 | SSE 7 | — | — | NNW 4 | NNW 6 | NW 7 | NW 8 | NW 7 | NNW 6 | — | — | SSW 13 | S 7 | S 6 | S 7 | SSE 6 |
340 | 529 | 285 | 302 | 280 | 256 | — | — | 33 | 329 | 396 | 145 | 128 | 17 | — | — | 1830 | 181 | 104 | 226 | 127 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 400 | 0 | 0 | 6 | 0 | 0 | 14 | 34 | 232 | 192 | 29 | 232 | 340 | 0 | 56 | 56 | 0 | 0 | 400 | 0 |
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.










