Surf Forecasts:
Big Bay surf forecast from 16 Sep 2026:
- Best quality surf: Friday 18 Sep, 2AM (local time) - 5ft (1.6m), 11s period, SW swell with offshore winds.
- Most powerful swell: Wednesday 16 Sep, 8AM (local time) - 10ft (3.0m), 13s period, WSW swell with 2,678 kJ wave energy.
- Next surfable swell (1★+): Friday 18 Sep, 2AM (local time) - 5ft (1.6m), 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 Friday (Sep 18) at 2AM. The primary swell is predicted to be 1.6m and 11s period with a secondary swell of 1.5m and 6s. The wind is predicted to be offshore as the swell arrives.
The most powerful waves expected at Big Bay in the next 16 days are 3.0m 13s and forecast to arrive on Wednesday (Sep 16) at 8AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.6m 6s period and expected on Saturday (Sep 19) at 2PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Fri 18th Sep) | 5ft (1.6m) 11s |
| Best Surf | 2AM (Fri 18th Sep) | 5ft (1.6m) 11s |
| Most Powerful | 8AM (Wed 16th Sep) | 10ft (3.0m) 13s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright surfers, Rusty here.
It’s a slow burner this time around for Big Bay, but there’s some proper juice coming if you’re patient. The first real surfable day isn’t until Wednesday the 18th, so don't bother paddling out before then.
The standout window is obviously Thursday the 19th and Friday the 20th of September, but the absolute gem of the whole 16-day stretch is Sunday the 29th.
Let’s get into it.
Wednesday the 18th morning – finally a pulse. A 5ft SW swell arrives with the SE wind dropping to just 9 mph. The energy is moderate at 729, and it’s clean. Not a world-beater, but a start.
Thursday the 19th keeps it going. Morning sees a 7ft SW swell, clean and cross-off with a fresh 22 mph SE breeze. The water temp is a chilly 55°F, which is nearly 5° colder than the norm for this time of year – that’s pretty unusual. You’ll want the thickest rubber you’ve got. Afternoon drops to 6ft, still clean.
Friday the 20th – the wind goes offshore at 9 mph, which is a huge bonus. A 5ft SW swell, moderate energy at 685, and clean conditions. Good for intermediate surfers.
Saturday the 21st is a real highlight. Morning glass with a 6 mph SSE breeze, 5ft WSW swell, and “very good” surf conditions. The energy is low-moderate at 566, but the quality is high.
Now, mark your calendar for Sunday the 29th of September. This is the one. A near-glassy 5 mph S wind, a solid 8ft SW groundswell with a 13-second period, and strong energy at 2170. This is proper, powerful surf for experienced surfers only. At 8ft in the afternoon, it’s too big for beginners. That long period will make it wrap and barrel, but it also means long waits between sets and a strong rip. Be ready.
Remember, Big Bay is an exposed break, and with a crowd rating of “often,” expect company on a Sunday like that. But the quality will be worth the crowd.
Before that, Thursday the 26th and Friday the 27th bring a massive 12ft SW swell, but the winds are cross-onshore or onshore, and the conditions are marginal. The combined wave energy is extreme (over 4600), but it’s going to be a messy, choppy beast. That’s kite-surfing territory, not paddle surfing.
We wind down into early October with a glassy morning on Thursday the 3rd. A small 5ft WSW swell, zero wind – clean, but small.
Your pick of the run: Sunday the 29th of September for size and glass. Saturday the 21st for cleaner, more manageable waves.
Stay keen.
Rusty
Short Range ForecastMostly dry. Very mild (max 19°C on Fri afternoon, min 12°C on Wed night). Winds decreasing (strong winds from the SSE on Wed afternoon, light winds from the ESE by Fri morning). | Days 4-6 Weather SummaryMostly dry. Warm (max 23°C on Mon afternoon, min 15°C on Sat morning). Winds decreasing (fresh winds from the SE on Sat afternoon, light winds from the ESE by Mon night). | ||||||||||||||||||||
Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | Monday 21 | Tuesday 22 | |||||||||||||||
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) | SW 13 | WSW 13 | SW 13 | SW 12 | SW 12 | SW 11 | SW 11 | SW 13 | SW 12 | SW 12 | SW 12 | SW 13 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | WSW 12 | SW 11 | SW 11 | SW 12 | SW 10 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2561 | 919 | 1352 | 1180 | 945 | 685 | 640 | 796 | 811 | 514 | 449 | 1496 | 1216 | 848 | 657 | 545 | 456 | 283 | 263 | 287 | 313 |
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 | off | cross-off | off | cross-off | off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | glassy | cross | cross-off |
High Tide | 6:00PM1.27m | 6:24AM1.13m | 6:36PM1.13m | 7:10AM1.01m | 7:30PM1.00m | 8:48AM0.92m | 9:37PM0.93m | 11:20AM0.96m | 11:39PM0.99m | 12:26PM1.08m | 00:34AM1.10m | 1:02PM1.21m | 1:11AM1.22m | ||||||||
Low Tide | 11:48AM0.38m | 00:15AM0.41m | 12:20PM0.51m | 00:53AM0.53m | 1:03PM0.63m | 2:02AM0.64m | 2:56PM0.73m | 4:47AM0.65m | 5:47PM0.67m | 6:11AM0.55m | 6:42PM0.56m | 6:52AM0.44m | 7:17PM0.43m | ||||||||
 | |  | | | | | | | | | | | | | | | | |  |  | |
 | 6:43 | — | — | 6:43 | — | — | 6:41 | — | — | 6:39 | — | — | 6:39 | — | — | 6:37 | — | — | 6:35 | — | — |
 | — | 6:37 | — | — | 6:37 | — | — | 6:38 | — | — | 6:39 | — | — | 6:39 | — | — | 6:40 | — | — | 6:42 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 15 | 16 | 14 | 15 | 17 | 14 | 16 | 19 | 15 | 19 | 21 | 17 | 19 | 20 | 16 | 21 | 23 | 21 | 24 | 23 | 21 |
Feels °C | 7 | 8 | 7 | 7 | 9 | 6 | 12 | 13 | 10 | 14 | 15 | 12 | 16 | 16 | 14 | 20 | 21 | 20 | 24 | 21 | 20 |
Swell 1 Height (m) Direction Period (s) | SW 13 | WSW 13 | SW 13 | SW 12 | SW 12 | SW 11 | SW 11 | SW 13 | SW 12 | SW 12 | SW 12 | SW 13 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | WSW 12 | SW 11 | SW 11 | SW 12 | SW 10 |
| kJ | 2561 | 901 | 1352 | 1180 | 945 | 685 | 640 | 796 | 811 | 514 | 449 | 1496 | 1216 | 848 | 657 | 545 | 456 | 283 | 263 | 287 | 313 |
Swell 2 Height (m) Direction Period (s) | SW 14 | SW 13 | W 13 | — | — | — | W 20 | SW 18 | SW 16 | SW 15 | SW 15 | — | — | — | — | S 5 | S 6 | SW 14 | SW 13 | WSW 11 | SE 8 |
| kJ | 534 | 919 | 324 | — | — | — | 7 | 12 | 41 | 171 | 212 | — | — | — | — | 21 | 26 | 99 | 175 | 133 | 3 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | SW 18 | — | — | — | — | — | SSW 15 | S 5 | SE 7 | SE 7 | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 53 | — | — | — | — | — | 21 | 14 | 11 | 2 | — |
Wind waves Height (m) Direction Period (s) | — | S 6 | SSE 8 | SSE 7 | S 6 | SSE 6 | SSE 7 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | — | SSE 6 | — | — | WNW 3 | WSW 4 |
| kJ | — | 245 | 395 | 298 | 345 | 181 | 82 | 298 | 74 | 132 | 272 | 190 | 130 | 212 | 56 | — | 55 | — | — | 4 | 20 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 340 | 163 | 56 | 400 | 1409 | 0 | 0 | 1976 | 0 | 7 | 163 | 190 | 0 | 400 | 0 | 0 | 0 | 0 | 0 | 0 | 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.
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