
Surf Forecasts:
Big Bay surf forecast from 14 Sep 2026:
- Best quality surf: Thursday 17 Sep, 5AM (local time) - 7.5ft (2.3m), 13s period, SW swell with offshore winds.
- Most powerful swell: Wednesday 16 Sep, 2AM (local time) - 10ft (3.0m), 14s period, WSW swell with 3,929 kJ wave energy.
- Next surfable swell (1★+): Thursday 17 Sep, 5AM (local time) - 7.5ft (2.3m), 13s 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 Thursday (Sep 17) at 5AM. The primary swell is predicted to be 2.3m and 13s period with a secondary swell of 0.8m and 12s. Another secondary swell of 1.5m and 7s is also forecast. 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 14s and forecast to arrive on Wednesday (Sep 16) at 2AM. Winds are predicted to be cross-shore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 6s period and expected on Wednesday (Sep 16) at 8PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 5AM (Thu 17th Sep) | 7.5ft (2.3m) 13s |
| Best Surf | 5AM (Thu 17th Sep) | 7.5ft (2.3m) 13s |
| Most Powerful | 2AM (Wed 16th Sep) | 10ft (3.0m) 14s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright, let’s get into it. The surf window is pretty quiet for the next few days, but there’s a solid run of waves building into the end of the week and beyond. Let’s break it down.
Right now, Monday afternoon into Tuesday is a write-off at Big Bay. We’ve got a fresh cross-onshore breeze and lumpy 5 to 6 ft NW windswell with short 7-second periods. Combined energy is weak at 563 (Monday) and 492 (Tuesday morning). The water temperature is 55°, which is 5° colder than normal for this time of year – that’s a notable chill, so you’ll want a thick wetsuit. Tuesday afternoon sees a pulse of longer period SW groundswell (16 seconds) and the combined energy jumps to 1218, but it’s still cross-onshore and lumpy. Not worth paddling out.
Wednesday the 16th and Thursday the 17th look cleaner with cross-off winds and 5 to 7 ft WSW/SW swell, periods around 12-13 seconds. But the wind is strong – 22 to 25 mph – so while it looks tidy from the beach, it’s going to be challenging out there. The combined energy is strong, between 1629 and 2327, but the score is marginal at best. This is more of a kite-surfing setup than a relaxing paddle session. Beginners should sit this out; the swell is over 5 ft and pushing toward 7 ft, so it’s only for experienced surfers.
Friday the 18th morning is a standout. Offshore wind from the SE at 16 mph, 6 ft SW swell with an 11-second period, combined energy at 828 – moderate but clean. Conditions are described as moderate offshore and clean. This is the best of the early window: not huge, but clean, with good shape. Expect some crowd factor at Big Bay as it’s often busy.
Saturday the 19th morning is similar but smaller – 4 ft SW, 12 seconds, offshore wind. Clean but less energy. Sunday the 20th sees the wind turning cross-off again and the swell picking back up to 6 ft, but it’s not quite as good as Friday.
Now, into the following week: Monday the 21st morning has light cross-off wind, 4 ft WSW swell at 12 seconds, and combined energy of 487 – weak, but the wind is light and the surf is clean. Not a standout but a fun small-wave session.
The real highlight comes on Tuesday the 22nd. Tuesday morning has 4 ft SW swell at 13 seconds, light wind, and very good surf conditions. Combined energy is 901 – moderate. Tuesday afternoon is even better: 4 ft SSW groundswell, 13-second period, gentle breeze, and excellent conditions for experienced surfers. Combined energy jumps to 1120. This is the best on offer – clean, well-shaped waves with that longer period making for smooth, lined-up sets. The optimum swell direction is SW and the guidance says the break is exposed to SW, so this is a perfect match. Expect crowds to be likely.
Wednesday the 23rd and Thursday the 24th are both clean but smaller. Thursday morning is a nice surprise – 4 ft SW, 13 seconds, offshore ESE wind at 9 mph, very good conditions. Light crowd factor, clean waves.
The final weekend, the 27th and 28th, looks promising again. Sunday the 27th has offshore wind both morning and afternoon, 4 to 5 ft SW/WSW swell at 13 seconds, moderate energy, very good conditions. Monday the 28th morning has 3 ft SW swell with a very long 16-second period, light wind, very good conditions – a classic long-period groundswell that will wrap nicely into the point.
The second week has some smaller days, but Tuesday the 22nd and Sunday the 27th are the ones to circle. Friday the 18th is the best early option.
Rusty
Short Range ForecastHeavy rain (total 21mm), heaviest during Tue night. Very mild (max 17°C on Mon afternoon, min 11°C on Tue night). Mainly strong winds. | Days 5-7 Weather SummaryMostly dry. Very mild (max 19°C on Fri afternoon, min 13°C on Thu night). Mainly strong winds. | |||||||||||||||||||
Mon 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | Saturday 19 | Sunday 20 | ||||||||||||||
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) | NW 7 | NW 8 | NW 6 | SW 16 | WSW 14 | WSW 13 | WSW 13 | SSW 13 | SW 12 | SW 12 | SW 11 | SW 11 | SW 13 | SW 13 | SW 12 | SW 12 | SW 13 | SW 13 | WSW 14 | WSW 13 |
Wave Graph | ||||||||||||||||||||
275 | 227 | 175 | 813 | 3929 | 878 | 1011 | 2345 | 1276 | 990 | 685 | 701 | 976 | 946 | 455 | 558 | 535 | 796 | 1080 | 689 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off | off | cross-off | cross-off | cross-off | cross-off | cross-off |
High Tide | 4:59PM1.52m | 5:18AM1.35m | 5:29PM1.40m | 5:49AM1.24m | 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 | |||||||
Low Tide | 11:15PM0.17m | 11:18AM0.26m | 11:44PM0.28m | 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 | ||||||||
— | — | 6:46 | — | — | 6:43 | — | — | 6:43 | — | — | 6:41 | — | — | 6:39 | — | — | 6:39 | — | — | |
6:36 | — | — | 6:37 | — | — | 6:37 | — | — | 6:37 | — | — | 6:38 | — | — | 6:39 | — | — | 6:39 | — | |
mm | 1 | 1 | — | — | 19 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 17 | 15 | 16 | 16 | 14 | 15 | 16 | 14 | 15 | 17 | 14 | 17 | 19 | 15 | 19 | 19 | 17 | 17 | 18 | 15 |
Feels °C | 10 | 11 | 9 | 9 | 10 | 7 | 7 | 6 | 7 | 10 | 7 | 11 | 12 | 9 | 14 | 14 | 12 | 11 | 11 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 12 | SW 12 | SW 11 | SW 16 | WSW 14 | WSW 13 | WSW 13 | SSW 13 | SW 12 | SW 12 | SW 11 | SW 11 | SW 13 | SW 13 | SW 12 | SW 12 | SW 13 | SW 13 | WSW 14 | WSW 13 |
272 | 220 | 165 | 813 | 3929 | 878 | 1011 | 2345 | 1276 | 990 | 685 | 701 | 976 | 946 | 455 | 558 | 535 | 796 | 1080 | 689 | |
Swell 2 Height (m) Direction Period (s) | SSE 13 | SE 13 | SW 18 | — | NW 7 | SW 14 | SW 13 | W 13 | W 12 | SSW 11 | SSW 10 | — | — | SW 16 | SW 14 | SW 15 | — | — | — | W 19 |
16 | 7 | 152 | — | 156 | 596 | 905 | 389 | 106 | 222 | 34 | — | — | 203 | 301 | 171 | — | — | — | 7 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | NW 7 | NW 8 | NW 6 | WNW 7 | — | SW 9 | S 6 | SE 6 | S 7 | S 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 | S 6 | S 6 | S 6 |
275 | 227 | 175 | 405 | — | 853 | 193 | 118 | 247 | 297 | 188 | 127 | 252 | 143 | 233 | 269 | 205 | 139 | 157 | 89 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 79 | 36 | 232 | 192 | 129 | 340 | 163 | 56 | 166 | 400 | 58 | 7 | 1409 | 0 | 129 | 400 | 456 | 163 | 861 | 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.










