Surf Forecasts:
Big Bay surf forecast from 18 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: Sunday 23 Aug, 2AM (local time) - 10ft (3.0m), 13s period, SW swell with 3,201 kJ wave energy.
- Next surfable swell (1★+): Wednesday 19 Aug, 2AM (local time) - 10ft (3.0m), 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 2AM. The primary swell is predicted to be 3.0m 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 Sunday (Aug 23) at 2AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 5s period and expected on Tuesday (Aug 25) at 8AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 2AM (Wed 19th Aug) | 10ft (3.0m) 12s |
| Best Surf | 8AM (Thu 20th Aug) | 10ft (3.0m) 13s |
| Most Powerful | 2AM (Sun 23rd Aug) | 10ft (3.0m) 13s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright folks, Rusty here, dialling in from the coast. We've got a solid run of south-west swells lining up for Big Bay, so let's get into it.
The pattern is locked in with a long-period SW groundswell that’s got some serious grunt, especially for you experienced crew. The water temp is sitting about average for this time of year, which isn't too bad. The first real standout is going to be Thursday morning, the 20th of August. We're looking at a solid 10ft swell from the SW, with a 13-second period, and the wind is a light cross-offshore breeze. That means it's clean, powerful and pushing through with heaps of energy (3126). This is a big one – only for the experienced crowd. The crowd factor leans towards “often” here, so there'll be plenty of others with the same idea.
Wednesday morning on the 19th of August is a good warm-up, 8ft SW swell at 12 seconds, clean and cross-offshore. Still sizeable, but a little less juice. Sunday morning the 23rd of August is another cracker – 8ft from the WSW, 13-second period and that beautiful light cross-off wind. The energy’s up there (2329) and the conditions will be pristine for a Sunday session. Through the following week, the swell stays solid but tends to get a bit messy with cross-onshore breezes developing. The energy remains moderate to strong.
There’s a notable gap coming up at the very end of the month. From the 30th of August through to the 1st of September, we’ve got strong, gusty SE and NW winds and the swell gets big and unruly, well over 8ft at times. It's not a total washout, but the wind will likely chop it up and conditions won’t be lined up like earlier in the run. The quality takes a real hit.
One to watch, but very much a long-range heads-up, is for the 3rd of September – Thursday morning. The models are hinting at a huge 16ft SW swell with a 14-second period. That’s massive energy (9687) and the wind looks light. However, at that size, Big Bay is only going to be for the absolute top-end experts. It's promising, but you know how these long-range calls can be. That’s about all the crystal ball has to offer.
Stay safe out there.
- Rusty
Short Range ForecastMostly dry. Very mild (max 18°C on Fri afternoon, min 11°C on Thu night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Very mild (max 17°C on Mon afternoon, min 12°C on Fri night). Wind will be generally light. | ||||||||||||||||||
Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | Monday 24 | ||||||||||||||
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 12 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | WSW 11 | SSW 11 | SW 10 | SW 13 | WSW 13 | WSW 12 | SW 12 | WSW 12 | WSW 11 | SW 14 |
Wave Graph  | |||||||||||||||||||
 kJ | 2379 | 1866 | 1638 | 1591 | 3126 | 2407 | 1513 | 882 | 444 | 345 | 281 | 825 | 3201 | 2329 | 1969 | 1423 | 660 | 447 | 813 |
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-off | cross-on | glassy | cross-on | on | off | cross-off | cross | cross-off | cross-off | cross-off | cross-off |
High Tide | 7:12AM1.10m | 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 | |||||||
Low Tide | 1:08AM0.42m | 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 | |||||||
 |  | | | | | | | | |  | | | | | | | | | |
 | — | 7:20 | — | — | 7:20 | — | — | 7:18 | — | — | 7:16 | — | — | 7:16 | — | — | 7:15 | — | — |
 | 6:17 | — | 6:19 | — | — | 6:19 | — | — | 6:20 | — | — | 6:21 | — | — | 6:21 | — | — | 6:22 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 13 | 14 | 16 | 14 | 15 | 16 | 13 | 15 | 18 | 14 | 15 | 15 | 15 | 14 | 16 | 13 | 15 | 17 | 15 |
Feels °C | 10 | 11 | 12 | 12 | 13 | 13 | 10 | 13 | 17 | 13 | 12 | 12 | 15 | 12 | 14 | 11 | 13 | 14 | 12 |
Swell 1 Height (m) Direction Period (s) | SW 12 | SW 12 | SW 12 | SW 12 | SW 13 | SW 13 | SW 12 | SW 11 | SSW 11 | SSW 10 | SSW 11 | SW 10 | SW 13 | WSW 13 | WSW 12 | SW 12 | WSW 12 | WSW 11 | SW 14 |
| kJ | 2379 | 1866 | 1638 | 1591 | 3126 | 2407 | 1513 | 882 | 444 | 345 | 281 | 825 | 3201 | 2329 | 1969 | 1423 | 660 | 447 | 813 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | — | S 6 | WSW 11 | WSW 11 | WSW 11 | WSW 16 | — | — | — | — | SSW 10 | SSW 10 | WSW 11 |
| kJ | — | — | — | — | — | — | — | 47 | 386 | 317 | 214 | 27 | — | — | — | — | 245 | 267 | 240 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | SSW 13 | — | — | — | — | — | SW 13 | SW 14 | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 69 | — | — | — | — | — | 46 | 92 | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | SE 4 | — | — | — | N 3 | — | — | — | — | SSE 3 | SSE 3 | S 4 | SSW 10 |
| kJ | — | — | — | — | — | — | 16 | — | — | — | 5 | — | — | — | — | 6 | 5 | 22 | 500 |
Nearest Offshore or Glassy | |||||||||||||||||||
Distance (km) | 0 | 0 | 6 | 0 | 0 | 52 | 0 | 0 | 14 | 0 | 4 | 29 | 0 | 0 | 0 | 0 | 0 | 2 | 0 |
Best forecast wave conditions in Cape Town | |||||||||||||||||||
Best forecast wave conditions in South Africa | |||||||||||||||||||
Header Global | |||||||||||||||||||
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Big Bay surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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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