
Surf Forecasts:
Big Bay surf forecast from 9 Sep 2026:
- Best quality surf: Thursday 10 Sep, 5AM (local time) - 4.5ft (1.3m), 16s period, SW swell with cross-offshore winds.
- Most powerful swell: Wednesday 16 Sep, 5AM (local time) - 13ft (4.0m), 16s period, WSW swell with 7,616 kJ wave energy.
- Next surfable swell (1★+): Wednesday 9 Sep, 11AM (local time) - 3ft (0.9m), 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 Wednesday (Sep 09) at 11AM. The primary swell is predicted to be 0.9m and 13s period with a secondary swell of 0.3m and 9s. 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 4.0m 16s and forecast to arrive on Wednesday (Sep 16) at 5AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.1m 5s period and expected on Friday (Sep 11) at 2AM.
| Wave Type | Time (SAST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 11AM (Wed 9th Sep) | 3ft (0.9m) 13s |
| Best Surf | 5AM (Thu 10th Sep) | 4.5ft (1.3m) 16s |
| Most Powerful | 5AM (Wed 16th Sep) | 13ft (4.0m) 16s |
Table - best surf conditions forecast for Big Bay over the next 16 days.
The Lowdown
Alright, grab your board and let’s talk about Big Bay. First, the water's freezing—53°, which is a solid 7° colder than usual for this time of year. That’s not a wetsuit thing, that’s a hood and booties thing. You’ll feel that sting on the paddle out.
We’ve got a bit of a slow burn to start. Nothing really happening until Wednesday the 10th, so don’t rush out before that. From the 10th on, we’re looking at a solid run of SW groundswell with moderate energy (2215), with 8ft of swell. It’s a bit much for the learning crowd, but for the guys who know what they’re doing, Thursday and Saturday are the pick of the first week. The Saturday afternoon pulse bumps up to 8ft with a 17-second period—that’s proper long-period energy, and the energy readings are strong (4064). It’ll be lined up, but that long period can make it a bit walled at a straight beach break; it’s a session for the experienced.
By Sunday the 13th, the wind goes glassy early. 7ft of SW swell with that clean surface is a great morning. The swell direction is a touch more WSW, which isn’t perfect for this exposure, but it’ll still be fun. Don't get too comfortable though—Monday and Tuesday turn into a write-off. Strong cross-onshore winds (up to 25 mph), lumpy, messy, and the swell gets mixed up with a short period NW windswell. It’s going to be a mess. That Monday, there’s even a bit of rain. Hard pass.
Then we get the standout run. From the 16th through the 19th, things really fire. The morning of the 16th has 12ft of WSW swell and strong energy (5371), but with 15 mph cross-off winds, it’s going to be big and challenging. The 17th is still big at 8ft, but cleaner. Honestly, the best bang for your buck looks like the 18th morning: 5ft of clean swell, light ENE wind, and that glassy surface. That’s the one where you can just about have it to yourself if you get out early.
The last few days fade off a bit. The 21st and 22nd have some nice, clean, smaller waves (around 5ft) with offshore and calm winds, perfect for a longboard or a fun twin fin. It’s a good way to end the run, but not a standout.
So, to keep it simple: if you’re an expert, the 16th and 17th are your days. For the rest of us, lock in the 18th morning, and maybe the 21st if you want a cruisy session. The rest is either too small, too blown out, or too gnarly. The window is there, you just gotta pick your moment.
Rusty.
Short Range ForecastMostly dry. Warm (max 23°C on Wed afternoon, min 14°C on Wed night). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 11mm), heaviest on Mon morning. Warm (max 20°C on Sat afternoon, min 14°C on Mon night). Winds increasing (calm on Sun morning, fresh winds from the N by Mon night). | ||||||||||||||||||||
Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | |||||||||||||||
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 | SW 12 | SW 15 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | S 8 | SW 15 | SW 17 | SW 15 | SW 14 | SW 13 | SW 13 | SW 12 | NW 7 | NW 8 | SW 21 | SW 18 | WSW 16 |
Wave Graph | |||||||||||||||||||||
304 | 295 | 607 | 2215 | 1672 | 1321 | 830 | 605 | 337 | 1325 | 3515 | 2010 | 1429 | 1014 | 600 | 380 | 305 | 345 | 1031 | 2690 | 7474 | |
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-off | cross-off | cross-off | off | glassy | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-off |
High Tide | 2:15PM1.57m | 2:33AM1.51m | 2:51PM1.66m | 3:10AM1.55m | 3:25PM1.70m | 3:44AM1.55m | 3:58PM1.68m | 4:17AM1.52m | 4:29PM1.62m | 4:48AM1.45m | 4:59PM1.52m | 5:18AM1.35m | 5:29PM1.40m | ||||||||
Low Tide | 8:04AM0.12m | 8:31PM0.08m | 8:41AM0.05m | 9:08PM0.01m | 9:15AM0.02m | 9:42PM-0.01m | 9:48AM0.03m | 10:15PM0.01m | 10:19AM0.08m | 10:45PM0.07m | 10:49AM0.16m | 11:15PM0.17m | 11:18AM0.26m | 11:44PM0.28m | |||||||
6:54 | — | — | 6:52 | — | — | 6:50 | — | — | 6:50 | — | — | 6:48 | — | — | 6:47 | — | — | 6:46 | — | — | |
— | 6:32 | — | — | 6:32 | — | — | 6:34 | — | — | 6:35 | — | — | 6:36 | — | — | 6:36 | — | — | 6:37 | — | |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | 1 | — | — | 6 | — | 3 | — | — | 13 |
Temp °C | 21 | 23 | 16 | 17 | 19 | 15 | 18 | 18 | 17 | 18 | 20 | 17 | 20 | 20 | 16 | 15 | 18 | 15 | 16 | 17 | 15 |
Feels °C | 20 | 21 | 15 | 16 | 16 | 12 | 15 | 15 | 15 | 16 | 17 | 16 | 21 | 19 | 15 | 14 | 13 | 11 | 9 | 9 | 10 |
Swell 1 Height (m) Direction Period (s) | WSW 13 | WSW 13 | SW 12 | SW 15 | WSW 13 | WSW 13 | WSW 12 | WSW 12 | WSW 11 | SW 15 | SW 17 | SW 15 | SW 14 | SW 13 | SW 13 | SW 12 | SW 12 | SW 12 | SW 21 | SW 18 | WSW 16 |
304 | 295 | 607 | 2215 | 1672 | 1321 | 830 | 605 | 307 | 1325 | 3515 | 2010 | 1429 | 1014 | 600 | 380 | 272 | 268 | 1031 | 2690 | 7474 | |
Swell 2 Height (m) Direction Period (s) | S 9 | W 11 | SW 17 | — | — | — | — | — | SW 14 | SW 20 | — | S 9 | S 8 | S 8 | S 8 | S 7 | SSE 7 | — | SW 11 | SW 10 | — |
14 | 9 | 238 | — | — | — | — | — | 164 | 309 | — | 364 | 113 | 71 | 57 | 27 | 5 | — | 202 | 132 | — | |
Swell 3 Height (m) Direction Period (s) | W 11 | — | S 8 | — | — | — | — | — | SW 10 | SSW 20 | — | — | — | — | NW 5 | S 12 | — | W 20 | — | — | — |
21 | — | 1 | — | — | — | — | — | 28 | 261 | — | — | — | — | 14 | 3 | — | 8 | — | — | — | |
Wind waves Height (m) Direction Period (s) | S 3 | S 4 | S 4 | — | S 4 | S 5 | S 7 | S 7 | S 8 | S 9 | S 9 | SSE 8 | — | NNW 4 | — | NNW 6 | NW 7 | NW 8 | WNW 7 | WNW 8 | — |
4 | 26 | 10 | — | 13 | 53 | 294 | 352 | 337 | 393 | 549 | 445 | — | 18 | — | 87 | 305 | 345 | 435 | 600 | — | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 0 | 39 | 0 | 0 | 39 | 0 | 0 | 0 | 0 | 0 | 415 | 0 | 0 | 13 | 2 | 36 | 87 | 36 | 192 | 232 | 39 |
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.










