
Surf Forecasts:
Big Bay surf forecast from 12 Sep 2026:
- Best quality surf: Wednesday 16 Sep, 2AM (local time) - 10ft (3.0m), 14s period, WSW swell with cross-offshore winds.
- Most powerful swell: Wednesday 16 Sep, 2AM (local time) - 10ft (3.0m), 14s period, WSW swell with 3,595 kJ wave energy.
- Next surfable swell (1★+): Sunday 13 Sep, 2AM (local time) - 7.5ft (2.3m), 15s 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 Sunday (Sep 13) at 2AM. The primary swell is predicted to be 2.3m and 15s period with a secondary swell of 1.1m and 9s. Another secondary swell of 1.6m and 8s 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-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.7m 6s period and expected on Wednesday (Sep 16) at 5PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Sun 13th Sep) | 7.5ft (2.3m) 15s |
| Best Surf | 2AM (Wed 16th Sep) | 10ft (3.0m) 14s |
| 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, Rusty here, let's talk about what's coming up at Big Bay.
We’ve got a mixed bag to start, but hold onto your board because the second half of this outlook cleans right up. Things kick off pretty average, but if you’re patient, there’s some proper gold at the end.
Right now, this Sunday the 13th, we’ve got a solid 7ft SW groundswell rolling in with a long 14-second period. The energy is pumping with a reading of 1922, but the wind is light and cross, so it’s not going to be perfect. It’s rideable, but a bit messy. The water temp is about what you’d expect for this time of year.
Into Monday and Tuesday, it gets a bit grim. The wind kicks up strong from the NNW and NW, hitting 19 mph, and the swell drops off. The surf quality dives hard, with conditions labelled as poor, so I wouldn't bother paddling out. We're looking at a solid couple of days with nothing to offer.
Now, Wednesday the 16th shows a glimmer of hope. The swell bumps back up to 8ft from the WSW with 13-second period and the wind turns cross-offshore from the SSE. It's a bit raw with strong energy (2672), and it's clean, but there’s a big caveat: that 8ft is pushing into expert-only territory. It's also a bit of a beast, so if you’re not confident, sit this one out.
Thursday the 17th and Friday the 18th are where it starts to turn on for the intermediate crew. Clean, offshore winds from the SE at 19 mph, holding a consistent 6ft SW swell with 12-13 second periods. The energy stays moderate (around 1009-1092) but the conditions are glassy and clean. These are solid, reliable days with good shaped waves.
The real standout, the day you should mark in your calendar, is Saturday the 19th of September. Everything clicks. We’ve got a clean 7ft SW swell with a 14-second period, the wind is gentle offshore from the SE at just 9 mph, and the wave energy is strong at 1528. This is prime surf for experienced surfers. The wave quality is excellent and it’ll be clean as a whistle all morning. This is the pick of the entire period.
We get a bit of a lull on the 20th and 21st with smaller 4ft swell and more cross-shore chop, but then we get another beautiful run from the morning of Tuesday the 23rd of September. The swell jumps to 8ft from the SW with 13-second period, winds are light and cross-offshore, and the energy is pumping at 1750. This is another excellent day for experienced surfers, with clean, powerful lines.
The end of the outlook has some solid waves, too, with a massive 10ft on the afternoon of the 24th from a short period S swell. That’s a lot of energy (3175), but with only 9 seconds between waves, it’s going to be fat and gutless on the face, better for a kite than a paddle. The 25th also holds a solid 8ft from the SSW with offshores, but it’s for the experienced crew only.
All in all, the first week is a bit of a struggle, but the second half of the period delivers some absolute gems. Focus on the 19th and the 22nd-23rd for the best of it.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Sun night. Warm (max 21°C on Sun morning, min 14°C on Mon night). Winds increasing (light winds from the NNE on Sun morning, fresh winds from the NW by Tue afternoon). | Days 5-7 Weather SummaryModerate rain (total 19mm), heaviest on Tue night. Very mild (max 19°C on Fri afternoon, min 12°C on Tue night). Winds increasing (light winds from the NNE on Tue night, fresh winds from the SE by Fri afternoon). | ||||||||||||||||||
Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | Friday 18 | ||||||||||||||
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 15 | SW 14 | SW 14 | SW 13 | SW 12 | SW 12 | SW 12 | NW 7 | SW 16 | WSW 14 | WSW 13 | SW 13 | SW 13 | SW 12 | WSW 12 | SW 12 | SW 13 | SW 14 | SW 13 |
Wave Graph | |||||||||||||||||||
2208 | 1812 | 1119 | 663 | 430 | 355 | 254 | 174 | 1014 | 3595 | 2084 | 851 | 897 | 865 | 743 | 710 | 1083 | 1150 | 932 | |
Wind (km/h) | |||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | cross | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-off | cross-off | cross-off | off | off | cross-off | cross-off | off | off | off |
High Tide | 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 | 7:10AM1.01m | 7:30PM1.00m | |||||||
Low Tide | 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 | 1:03PM0.63m | 2:02AM0.64m | ||||||
— | 6:48 | — | — | 6:47 | — | — | 6:46 | — | — | 6:43 | — | — | 6:43 | — | — | 6:41 | — | — | |
6:35 | — | 6:36 | — | — | 6:36 | — | — | 6:37 | — | — | 6:37 | — | — | 6:37 | — | — | 6:38 | — | |
mm | — | — | — | 4 | 2 | — | — | — | — | 18 | 1 | — | — | — | — | — | — | — | — |
Temp °C | 18 | 21 | 17 | 16 | 17 | 17 | 15 | 16 | 16 | 15 | 13 | 15 | 13 | 16 | 18 | 14 | 17 | 19 | 15 |
Feels °C | 16 | 21 | 16 | 16 | 13 | 12 | 11 | 11 | 10 | 12 | 8 | 8 | 5 | 9 | 11 | 9 | 10 | 12 | 9 |
Swell 1 Height (m) Direction Period (s) | SW 15 | SW 14 | SW 14 | SW 13 | SW 12 | SW 12 | SW 12 | SW 11 | SW 16 | WSW 14 | WSW 13 | SW 13 | SW 13 | SW 12 | WSW 12 | SW 12 | SW 13 | SW 14 | SW 13 |
2208 | 1812 | 1119 | 663 | 430 | 355 | 254 | 165 | 1014 | 3595 | 2084 | 851 | 897 | 865 | 743 | 710 | 1083 | 1150 | 932 | |
Swell 2 Height (m) Direction Period (s) | SSE 9 | SSE 8 | S 7 | S 7 | SE 9 | SSE 8 | — | SW 18 | WSW 7 | NW 6 | SW 14 | WSW 13 | W 13 | W 12 | — | — | W 11 | WSW 18 | SW 16 |
193 | 110 | 50 | 24 | 19 | 6 | — | 157 | 59 | 43 | 588 | 823 | 468 | 144 | — | — | 9 | 31 | 302 | |
Swell 3 Height (m) Direction Period (s) | — | — | SSE 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
— | — | 12 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | SSE 8 | — | — | NNW 4 | NW 5 | NW 6 | NW 7 | NW 7 | NW 6 | — | — | S 6 | SSE 6 | SSE 6 | S 6 | SSE 6 | SSE 6 | SSE 6 | SSE 6 |
302 | — | — | 11 | 43 | 151 | 212 | 174 | 143 | — | — | 203 | 193 | 198 | 328 | 155 | 145 | 215 | 60 | |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 2 | 15 | 2 | 36 | 185 | 79 | 192 | 455 | 0 | 56 | 56 | 0 | 166 | 400 | 0 | 129 | 122 | 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.










