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★+): Thursday 20 Aug, 2AM (local time) - 8ft (2.4m), 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 Thursday (Aug 20) at 2AM. The primary swell is predicted to be 2.4m 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 1.6m 6s period and expected on Monday (Aug 24) at 11PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Thu 20th Aug) | 8ft (2.4m) 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
Alright folks, Rusty here. Let’s get into it for Big Bay.
We’ve got a solid run of surf ahead, kicking off this Thursday morning with a proper swell. The water temp is about average for this time of year, so nothing unusual there. The south-west swell is pulsing in at 10ft with a 13-second period, and the combined energy is strong (3422). That’s a hefty groundswell. The wind is a cross-off from the south, keeping it clean. This is big, powerful surf – definitely for experienced surfers only. The afternoon sees it drop back a touch, and the quality fades.
Friday morning still has decent size at 6ft from the south-west, with that clean cross-off wind holding. The energy is moderate (921). It’s a good window for the intermediate crew. By Friday afternoon the swell drops and the wind swings, making it a bit more average.
Saturday is a write-off. The swell is small and the wind is onshore. Don’t bother.
Now, Sunday the 23rd looks like a standout. The swell builds back to 7ft from the west-south-west with a 13-second period, and the energy is strong (1548). The wind stays cross-off and light, so it’ll be clean. Excellent conditions for experienced surfers again. Monday morning and Tuesday morning are also in the mix with clean, cross-off winds and a solid 5ft to 7ft swell. Tuesday morning even gets a gentle offshore breeze from the south-east, which is a real treat.
The next big highlight is Friday the 28th of August. It’s a morning session with a 7ft west-south-west groundswell, a 14-second period, and a gentle offshore wind from the south-east. The energy is strong (1890). That’s a quality, clean wave for the experienced.
The following Sunday the 30th is special. The wind goes completely glassy in the morning. It’s dead calm. The swell is a clean 5ft from the west-south-west. That’s a rare, perfect window for anyone who can handle it.
Things get gnarly again on Monday the 31st. The swell cranks up to 12ft with a 13-second period and very strong energy (4241). The wind is light, but it’s cross-shore. This is only for the most experienced. The risks are high.
After that, the first few days of September are a write-off. Strong, onshore winds from the north-west make for poor, choppy conditions. The swell is still there, but the wind ruins it. It settles down a bit by Thursday the 3rd, but it’s not great.
The best of the best is the glassy session on Sunday morning the 30th of August. That’s the one to circle.
Rusty, signing off.
Short Range ForecastMostly dry. Very mild (max 19°C on Fri afternoon, min 11°C on Fri morning). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 25°C on Tue afternoon, min 12°C on Sun night). Wind will be generally light. | ||||||||||||||||||
Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | Tuesday 25 | ||||||||||||||
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 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 10 | SSW 12 | WSW 14 | WSW 13 | WSW 12 | WSW 12 | WSW 12 | WSW 11 | SW 15 | SW 14 | WSW 14 | SW 13 |
Wave Graph  | |||||||||||||||||||
 kJ | 1687 | 3422 | 2536 | 1610 | 882 | 444 | 388 | 339 | 397 | 630 | 1548 | 1498 | 1027 | 569 | 376 | 1138 | 1712 | 1598 | 1129 |
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 | cross | cross-on | cross-on | off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off | cross-off | cross-off |
High Tide | 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 | 1:55AM0.54m | 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 | — | — | 7:18 | — | — | 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 | 14 | 16 | 13 | 15 | 19 | 15 | 15 | 15 | 15 | 15 | 17 | 14 | 15 | 17 | 14 | 18 | 25 | 23 |
Feels °C | 12 | 11 | 13 | 10 | 13 | 18 | 14 | 13 | 13 | 15 | 14 | 15 | 12 | 12 | 13 | 11 | 14 | 22 | 20 |
Swell 1 Height (m) Direction Period (s) | SW 12 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 10 | SSW 12 | SSW 11 | WSW 13 | WSW 12 | WSW 12 | WSW 12 | WSW 11 | SW 15 | SW 14 | WSW 14 | SW 13 |
| kJ | 1687 | 3422 | 2536 | 1610 | 882 | 444 | 388 | 339 | 397 | 466 | 1548 | 1498 | 1027 | 569 | 376 | 1138 | 1712 | 1598 | 1129 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | S 6 | WSW 11 | WSW 11 | WSW 11 | WSW 10 | WSW 10 | — | — | — | SW 14 | SW 11 | WSW 11 | S 6 | — | S 7 |
| kJ | — | — | — | — | 39 | 379 | 317 | 214 | 166 | 386 | — | — | — | 93 | 220 | 194 | 92 | — | 51 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | SSW 14 | — | WSW 17 | WSW 14 | — | — | — | SSW 14 | SW 14 | SW 10 | — | — | — |
| kJ | — | — | — | — | — | — | 81 | — | 28 | 630 | — | — | — | 127 | 211 | 136 | — | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | SSE 4 | SSE 5 | — | — | — | — | — | — | — | S 5 | SSW 11 | S 5 | S 6 | SSE 6 | S 6 | — |
| kJ | — | — | — | 25 | 60 | — | — | — | — | — | — | — | 37 | 350 | 73 | 125 | 145 | 81 | — |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 0 | 52 | 0 | 0 | 14 | 0 | 29 | 29 | 0 | 0 | 0 | 0 | 0 | 91 | 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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