Surf Forecasts:
Big Bay surf forecast from 17 Aug 2026:
- Best quality surf: Thursday 20 Aug, 8AM (local time) - 11ft (3.5m), 13s period, SW swell with cross-offshore winds.
- Most powerful swell: Thursday 20 Aug, 8AM (local time) - 11ft (3.5m), 13s period, SW swell with 3,425 kJ wave energy.
- Next surfable swell (1★+): Monday 17 Aug, 11PM (local time) - 8ft (2.4m), 13s period with WSW 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 Monday (Aug 17) at 11PM. The primary swell is predicted to be 2.4m and 13s period. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Big Bay in the next 16 days are 3.5m 13s and forecast to arrive on Thursday (Aug 20) at 8AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.8m 4s period and expected on Friday (Aug 21) at 5PM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11PM (Mon 17th Aug) | 8ft (2.4m) 13s |
| Best Surf | 8AM (Thu 20th Aug) | 11ft (3.5m) 13s |
| Most Powerful | 8AM (Thu 20th Aug) | 11ft (3.5m) 13s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
G’day, Rusty here again. Let’s have a look at the next couple of weeks at Big Bay. Water’s proper cold, about 55°F, which is a solid 5°F colder than normal for this time of year—so you’ll be needing the thickest rubber you’ve got.
Monday the 17th is a washout. Swell’s pushing 8ft, but the cross-onshore wind has it chopped up and messy. Tuesday the 18th is the first real chance—clean waves around 8ft in the morning with a cross-off breeze. Good for the experienced crowd. Wednesday the 19th is a bit all over the place with cross winds and a weaker pulse. Thursday the 20th is where the size jumps—12ft in the morning, cross-off wind. That’s serious surf, only for the experts. Anything over 8ft is past beginner territory.
Friday the 21st is a touch smaller at 7ft, still clean. Saturday the 22nd is okay in the morning but gets chopped in the arvo. Sunday the 23rd is back to a clean 7ft. Monday the 24th drops to around 5ft to 5ft, still clean and a good option for a lighter session.
Now, the standout. Tuesday the 25th. Morning brings a clean 8ft from the SW, with a 13-second period and light cross-off winds. It’s got size and shape. This is one of the best days of the whole run. Wednesday the 26th is special too—the afternoon goes completely glassy with light winds and 6ft waves. Perfect conditions.
Thursday the 27th has some cross-on wind, so maybe sit it out. But Friday the 28th is another cracker—clean 8ft to 8ft with a longer 14-second period in the morning. That’s groundswell and it’s going to line up nicely. Another standout.
Saturday the 29th still has clean 8ft but with more wind. Sunday the 30th gets windy and the swell fades to 4ft in the morning. Not great. The long-range stuff—Monday the 31st and Tuesday the 1st—sees a big pulse of 12ft to 10ft with strong energy. Monday has clean cross-off winds, and Tuesday morning is glassy. These are for experts only, and being that far out, I’d call them promising but less certain.
So, the pick of the bunch is Tuesday the 25th and Friday the 28th, with the end of the month looking big and clean for the crew who can handle it. The gaps in between are short, maybe a day here or there. Expect crowds on the good days, that’s for sure.
Stay warm, stay safe.
Rusty.
Short Range ForecastMostly dry. Very mild (max 17°C on Mon afternoon, min 12°C on Tue night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Very mild (max 17°C on Sat afternoon, min 11°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Monday 17 | Tuesday 18 | Wednesday 19 | Thursday 20 | Friday 21 | Saturday 22 | Sunday 23 | |||||||||||||||
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) | WSW 13 | WSW 13 | WSW 13 | WSW 12 | SW 13 | SW 12 | SW 12 | SW 12 | SW 12 | SW 13 | SW 12 | SW 12 | SW 11 | WSW 11 | WSW 11 | SW 11 | SW 12 | SW 13 | WSW 13 | WSW 13 | WSW 12 |
Wave Graph  | |||||||||||||||||||||
 kJ | 2354 | 2026 | 1930 | 1735 | 2345 | 2379 | 1866 | 1550 | 1715 | 3267 | 2507 | 1524 | 1045 | 466 | 291 | 952 | 1632 | 1846 | 1407 | 1407 | 694 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-off | cross-off | cross-off | cross-off | cross | cross | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross-off | cross-off | cross-off | cross-off |
High Tide | 6:13PM1.43m | 6:32AM1.21m | 6:48PM1.29m | 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 | ||||||||
Low Tide | 11:57AM0.25m | 00:31AM0.30m | 12:30PM0.38m | 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 | ||||||||
 | |  |  | |  | | | | | | | | | | | | | | | | |
 | 7:22 | — | — | 7:22 | — | — | 7:20 | — | — | 7:20 | — | — | 7:18 | — | — | 7:16 | — | — | 7:16 | — | — |
 | — | 6:16 | — | — | 6:17 | — | — | 6:19 | — | — | 6:19 | — | — | 6:20 | — | — | 6:21 | — | — | 6:21 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 17 | 14 | 15 | 16 | 13 | 14 | 16 | 14 | 14 | 15 | 12 | 14 | 15 | 12 | 15 | 17 | 15 | 17 | 19 | 15 |
Feels °C | 15 | 15 | 13 | 13 | 13 | 10 | 12 | 12 | 12 | 12 | 12 | 9 | 12 | 11 | 8 | 14 | 15 | 14 | 15 | 16 | 12 |
Swell 1 Height (m) Direction Period (s) | WSW 13 | WSW 13 | WSW 13 | WSW 12 | SW 13 | SW 12 | SW 12 | SW 12 | SW 12 | SW 13 | SW 12 | SW 12 | SW 11 | WSW 11 | WSW 11 | SW 11 | SW 12 | SW 13 | WSW 13 | WSW 13 | WSW 12 |
| kJ | 2354 | 2026 | 1930 | 1735 | 2345 | 2379 | 1866 | 1550 | 1715 | 3267 | 2507 | 1524 | 1045 | 466 | 291 | 952 | 1632 | 1846 | 1407 | 1407 | 694 |
Swell 2 Height (m) Direction Period (s) | — | W 16 | SW 14 | SW 12 | — | — | — | — | — | — | — | — | — | SSW 11 | SSW 10 | — | — | — | — | SSW 11 | SSW 11 |
| kJ | — | 193 | 224 | 398 | — | — | — | — | — | — | — | — | — | 275 | 260 | — | — | — | — | 302 | 372 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | S 4 | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | 22 | — | — | — | — | — | — | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 2 | 29 | 0 | 0 | 52 | 0 | 0 | 14 | 0 | 0 | 400 | 0 | 0 | 39 | 0 | 0 | 10 | 0 | 0 | 39 | 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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