Surf Forecasts:
Big Bay surf forecast from 19 Aug 2026:
- Best quality surf: Thursday 20 Aug, 8AM (local time) - 10ft (3.0m), 13s period, SW swell with cross-offshore winds.
- Most powerful swell: Thursday 20 Aug, 11AM (local time) - 10ft (3.0m), 13s period, SW swell with 3,422 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 8PM (local time) - 7.5ft (2.3m), 12s 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 Wednesday (Aug 19) at 8PM. The primary swell is predicted to be 2.3m and 12s period. 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 13s and forecast to arrive on Thursday (Aug 20) at 11AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.4m 6s period and expected on Tuesday (Aug 25) at 2AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 8PM (Wed 19th Aug) | 7.5ft (2.3m) 12s |
| Best Surf | 8AM (Thu 20th Aug) | 10ft (3.0m) 13s |
| Most Powerful | 11AM (Thu 20th Aug) | 10ft (3.0m) 13s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Right folks, Rusty here. Let’s have a look at what Big Bay has got cooking for us over the next couple of weeks.
Overall, we’re looking at a feast-or-famine stretch. There’s a solid pulse of SW groundswell coming through mid-week, but it’s going to be a bumpy ride with the winds. The real standout is shaping up to be Thursday the 20th, with a big, powerful swell and light winds, but you’ll need your wits about you. After that, the energy drops off, then builds again for another serious pulse of swell rolling in around Saturday the 29th and into the first week of September. There’s a bit of a lull in energy after the first week’s pulse.
Right off the bat, Wednesday the 19th is a bit of a non-starter. There’s swell there, about 8ft from the SW, but the wind is cross-off and the conditions are just marginal. The water is at 55°, which is a fair whack colder than usual for this time of year – a full 5° below average, so you’ll be wanting a good thick steamer.
Now, Thursday the 20th is the real deal. The morning session is the pick of the first week. You’ve got a solid 10ft SW groundswell (combined energy of 3422), riding on a 13-second period, and the wind is light and cross-off. This is proper, powerful surf for experienced surfers only – it’s over 8ft and will be a handful. The afternoon has the same size but the wind picks up a fraction, so the morning window is your golden ticket.
Friday the 21st morning is still good – 7ft SW swell with light cross-off winds – still a big-wave but a bit more manageable. The afternoon gets a bit messy as the wind swings cross-shore.
Saturday the 22nd and Sunday the 23rd sees the swell drop off from the first pulse. Saturday is small and scrappy. Sunday sees a new 8ft pulse from the WSW roll in with clean, cross-off winds. It’s a solid size and looks fun, but the real power has gone.
Monday the 24th and Tuesday the 25th are both decent, with clean morning sessions. The swell holds around the 7ft mark from the SW-WSW and the wind is light offshore or cross-off. Good clean conditions for an intermediate surfer, but not the stand-out power of Thursday.
Wednesday the 26th is a bit of a write-off with a cross-on wind, so it’ll be bumpy. Thursday the 27th is much lighter, with a glassy afternoon that could be nice for a smaller board – only 4ft swell, but clean as a whistle.
There’s a bit of a lull on the Friday the 28th, with the wind getting on it again, but hold on for Saturday the 29th. This is the other big standout. The morning is packing 13ft from the SSW (combined energy of 4275) with a moderate offshore wind from the SE. This is a serious, expert-only swell. It’s big, powerful, and clean for a window. The afternoon drops a bit but is still huge and clean.
Sunday the 30th and Monday the 31st are blown out. The wind turns onshore or cross-on, making the big swell a messy, choppy affair. Not worth it.
Now, looking a week ahead to Tuesday the 1st of September. The forecast is looking promising for a big run of long-period groundswell. The morning is glassy with a 7ft WSW swell (combined energy of 1957) and a 14-second period. That’s a long period, which means better shaped waves but longer waits between sets. It could be a ripper. The afternoon stays clean with a light cross-off wind.
Thursday the 3rd of September is another potential standout to keep in mind. It’s a long way out, so take it with a pinch of salt, but the morning is showing a 10ft W groundswell (combined energy of 3983) with a glassy offshore wind. If that holds, it could be the best session of the whole outlook. The afternoon looks cross-on, so the window will be tight.
So, to sum it up: if you’re experienced, the top pick is the morning of Thursday the 20th. For the second week, keep an eye on the morning of Tuesday the 1st of September, and if you’re a real charger, the morning of Thursday the 3rd of September has serious potential.
Rusty.
Short Range ForecastMostly dry. Very mild (max 18°C on Fri afternoon, min 11°C on Fri morning). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Very mild (max 17°C on Mon afternoon, min 12°C on Sat morning). Wind will be generally light. | ||||||||||||||||||||
Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | |||||||||||||||
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 12 | SW 12 | SW 12 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 12 | SSW 12 | SW 10 | WSW 13 | WSW 12 | WSW 12 | SW 12 | WSW 11 | SW 14 | WSW 13 | WSW 13 | WSW 13 |
Wave Graph | |||||||||||||||||||||
1866 | 1550 | 1591 | 3422 | 2618 | 1513 | 1027 | 444 | 396 | 451 | 403 | 553 | 1726 | 1430 | 1010 | 974 | 383 | 1443 | 1401 | 1198 | 799 | |
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 | cross-off | cross-on | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off |
High Tide | 7:29PM1.15m | 8:07AM0.99m | 8:32PM1.04m | 9:49AM0.92m | 10:25PM0.98m | 11:54AM0.96m | 00:06AM1.04m | 12:58PM1.07m | 1:01AM1.13m | 1:36PM1.19m | 1:40AM1.24m | 2:08PM1.31m | 2:13AM1.33m | ||||||||
Low Tide | 1:06PM0.51m | 1:55AM0.54m | 1:57PM0.63m | 3:19AM0.62m | 3:53PM0.70m | 5:32AM0.61m | 6:08PM0.66m | 6:46AM0.52m | 7:07PM0.56m | 7:27AM0.41m | 7:45PM0.45m | 7:59AM0.30m | 8:17PM0.34m | ||||||||
7:20 | — | — | 7:20 | — | — | 7:18 | — | — | 7:16 | — | — | 7:16 | — | — | 7:15 | — | — | 7:13 | — | — | |
— | 6:19 | — | — | 6:19 | — | — | 6:20 | — | — | 6:21 | — | — | 6:21 | — | — | 6:22 | — | — | 6:22 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 14 | 16 | 14 | 15 | 16 | 13 | 15 | 18 | 15 | 15 | 16 | 15 | 15 | 16 | 13 | 15 | 17 | 14 | 21 | 27 | 25 |
Feels °C | 11 | 12 | 12 | 13 | 13 | 10 | 13 | 16 | 14 | 14 | 14 | 15 | 14 | 13 | 11 | 13 | 14 | 12 | 20 | 25 | 22 |
Swell 1 Height (m) Direction Period (s) | SW 12 | SW 12 | SW 12 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 12 | SSW 12 | SW 10 | WSW 13 | WSW 12 | WSW 12 | SW 12 | WSW 11 | SW 14 | WSW 13 | WSW 13 | WSW 13 |
1866 | 1550 | 1591 | 3422 | 2618 | 1513 | 1027 | 444 | 396 | 451 | 403 | 524 | 1726 | 1430 | 1010 | 974 | 383 | 1443 | 1401 | 1198 | 799 | |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | — | WSW 11 | WSW 11 | WSW 11 | WSW 10 | WSW 14 | — | — | — | SSW 15 | SW 10 | W 11 | SW 20 | SW 18 | SW 15 |
— | — | — | — | — | — | — | 386 | 317 | 176 | 166 | 553 | — | — | — | 84 | 276 | 119 | 15 | 111 | 418 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | SSW 14 | — | WSW 18 | SW 11 | — | — | — | — | SW 14 | — | — | SSW 11 | S 10 |
— | — | — | — | — | — | — | — | 81 | — | 30 | 182 | — | — | — | — | 301 | — | — | 39 | 188 | |
Wind waves Height (m) Direction Period (s) | — | S 3 | — | — | — | SE 4 | SSE 6 | SSE 6 | — | — | NNW 3 | — | — | — | S 4 | SSE 4 | S 5 | S 6 | S 6 | S 6 | SSE 6 |
— | 6 | — | — | — | 16 | 69 | 53 | — | — | 1 | — | — | — | 23 | 31 | 57 | 121 | 69 | 89 | 87 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 39 | 34 | 0 | 0 | 52 | 0 | 0 | 14 | 0 | 20 | 29 | 0 | 0 | 0 | 0 | 0 | 118 | 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.











