Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 28 Aug 2026:
- Best quality surf: Saturday 29 Aug, 10AM (local time) - 3ft (0.9m), 6s period, SSW swell with cross-offshore winds.
- Most powerful swell: Thursday 3 Sep, 1PM (local time) - 7ft (2.1m), 7s period, SW swell with 397 kJ wave energy.
- Next surfable swell (1★+): Saturday 29 Aug, 10AM (local time) - 3ft (0.9m), 6s period with SSW swell.
Best Forecast Surf Conditions for Cable Bay (Porth Trecastell) this week:
The surf forecast for Cable Bay (Porth Trecastell) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Aug 29) at 10AM. The primary swell is predicted to be 0.9m and 6s period. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Cable Bay (Porth Trecastell) in the next 16 days are 2.1m 7s and forecast to arrive on Thursday (Sep 03) at 1PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 4s period and expected on Saturday (Aug 29) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 10AM (Sat 29th Aug) | 3ft (0.9m) 6s |
| Best Surf | 10AM (Sat 29th Aug) | 3ft (0.9m) 6s |
| Most Powerful | 1PM (Thu 3rd Sep) | 7ft (2.1m) 7s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Right then, let’s have a look at what’s shaping up for the next couple of weeks at Cable Bay (Porth Trecastell).
To be honest, it’s a pretty grim run overall. The water temperature is sitting at 64°F right now, which is a solid 4°F above normal for this time of year – that’s much warmer than we’d usually expect, so you won’t be needing the thickest wetsuit, but that’s about the only good news.
For the first week, from Friday 28 August right through to the end of the first week of September, the swell is tiny and the wind is almost always onshore or cross-onshore. The wave energy is weak, often well under 100 (22 on the Friday morning, 19 in the afternoon). You’ll see a bit of a pulse around Monday 31 August morning with combined energy hitting 162, but it’s still cross-onshore with a messy 3ft wave. The best of a bad lot might be Saturday 29 August morning – a light ESE cross-offshore breeze, 3ft SSW swell, and the wave comment calling it “surfable waves but very ordinary conditions”. That’s about as good as it gets, and it’s still pretty average.
There’s a real gap from around Tuesday 1 September onwards – the swell drops off, and the wind just keeps swinging onshore. By Wednesday 2 September the breeze is up to 22 mph and the swell is only 5ft with poor conditions. The following days are just more of the same: onshore winds, small messy swell, and the wave energy stays moderate but never clean.
Then from Saturday 6 September afternoon, we see a slight flicker – 6ft SSW swell, light cross-onshore breeze, and the energy is moderate at 211. The wave comment says “marginal surf forecast or questionable tide conditions”, scoring a 2 out of 10. That’s the best score in the whole run, but it’s still marginal.
After that, it fades again. By Thursday 10 September the swell is gone completely – zero energy – and it stays that way through to Saturday 12 September, with only cross-offshore winds but no waves to ride.
So, if you’re desperate, the Saturday 29 August morning slot is your best bet – clean enough with a light offshore, but don’t expect much. Otherwise, it’s a long wait. The outlook is bleak, but the area is fairly consistent, so it won’t stay this poor forever. Keep an eye on the forecasts.
Rusty
Short Range ForecastModerate rain (total 12mm), heaviest on Sat morning. Very mild (max 18°C on Sun morning, min 15°C on Sat afternoon). Wind will be generally light. | Days 4-6 Weather SummaryModerate rain (total 11mm), heaviest on Wed morning. Very mild (max 18°C on Wed night, min 15°C on Mon morning). Winds increasing (light winds from the SW on Mon afternoon, fresh winds from the SSW by Wed morning). | ||||||||||||||||||||
Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | Tuesday 1 | Wednesday 2 | Thursday 3 | |||||||||||||||
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) | SSW 6 | SSW 6 | SSW 6 | SSW 6 | SSW 6 | SSW 9 | SSW 8 | SSW 5 | SSW 7 | SW 8 | SW 8 | SW 4 | WNW 4 | SW 6 | SW 6 | SW 3 | SSW 6 | SW 7 | SW 6 | SW 7 | SW 7 |
Wave Graph | |||||||||||||||||||||
16 | 16 | 41 | 60 | 20 | 157 | 48 | 48 | 105 | 88 | 77 | 18 | 32 | 20 | 9 | 10 | 190 | 100 | 236 | 305 | 121 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-on | cross-off | off | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | on | on | on | cross-on | on | cross-on |
High Tide | 10:23AM3.73m | 10:32PM4.18m | 10:51AM3.84m | 11:00PM4.28m | 11:19AM3.92m | 11:30PM4.30m | 11:49AM3.93m | 00:03AM4.23m | 12:23PM3.87m | 00:40AM4.07m | 1:01PM3.73m | 1:22AM3.82m | 1:47PM3.51m | 2:14AM3.50m | |||||||
Low Tide | 4:53PM0.30m | 5:18AM0.06m | 5:26PM0.21m | 5:52AM0.00m | 6:01PM0.20m | 6:27AM0.05m | 6:37PM0.27m | 7:03AM0.19m | 7:16PM0.42m | 7:43AM0.43m | 7:59PM0.63m | 8:28AM0.72m | 8:50PM0.88m | ||||||||
6:18 | — | — | 6:20 | — | — | 6:22 | — | — | 6:24 | — | — | 6:26 | — | — | 6:28 | — | — | 6:30 | — | — | |
— | 8:16 | — | — | 8:15 | — | — | 8:13 | — | — | 8:09 | — | — | 8:07 | — | — | 8:06 | — | — | 8:02 | — | |
mm | 2 | — | — | 4 | — | 1 | 1 | 4 | — | — | — | — | — | — | 3 | 4 | 3 | 1 | — | — | 1 |
Temp °C | 17 | 17 | 16 | 16 | 16 | 15 | 18 | 16 | 15 | 15 | 17 | 17 | 15 | 16 | 17 | 15 | 17 | 18 | 16 | 17 | 17 |
Feels °C | 16 | 15 | 14 | 16 | 15 | 14 | 14 | 12 | 12 | 11 | 16 | 15 | 12 | 14 | 14 | 12 | 15 | 16 | 11 | 11 | 11 |
Swell 1 Height (m) Direction Period (s) | SSW 6 | SSW 6 | SSW 6 | SSW 6 | SSW 6 | SSW 9 | SSW 8 | — | SSW 7 | SW 8 | SW 8 | NNW 4 | SW 5 | SW 6 | SW 6 | NNW 4 | SW 16 | SW 15 | — | SW 14 | SW 7 |
16 | 16 | 41 | 60 | 20 | 157 | 48 | — | 105 | 88 | 48 | 2 | 22 | 17 | 9 | 2 | 10 | 9 | — | 8 | 121 | |
Swell 2 Height (m) Direction Period (s) | S 12 | N 3 | — | — | — | NW 4 | WNW 3 | — | — | — | SW 8 | — | — | — | NNW 4 | S 16 | — | — | — | — | SW 14 |
3 | 2 | — | — | — | 3 | 1 | — | — | — | 77 | — | — | — | 4 | 5 | — | — | — | — | 8 | |
Swell 3 Height (m) Direction Period (s) | S 12 | S 11 | S 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SW 14 |
3 | 3 | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 8 | |
Wind waves Height (m) Direction Period (s) | NNW 3 | — | — | — | — | — | SSW 3 | SSW 5 | — | WNW 5 | NW 4 | SW 4 | WNW 4 | NW 4 | — | SW 3 | SSW 6 | SW 7 | SW 6 | SW 7 | WNW 4 |
1 | — | — | — | — | — | 4 | 48 | — | 74 | 24 | 18 | 32 | 20 | — | 10 | 190 | 100 | 236 | 305 | 12 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 277 | 282 | 277 | 0 | 172 | 44 | 248 | 285 | 44 | 297 | 44 | 173 | 333 | 294 | 244 | 256 | 256 | 283 | 285 | 381 | 393 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
Information about the Cable Bay (Porth Trecastell) Surf forecast
The above surf forecast table for Cable Bay (Porth Trecastell) provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Cable Bay (Porth Trecastell) can be found by selecting the local surf guide option on the grey menu. Our Cable Bay (Porth Trecastell) 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 (Cable Bay (Porth Trecastell)) 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 Cable Bay (Porth Trecastell) 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.
Are you planning a holiday in Anglesy? If you are looking for accommodation near Cable Bay, camping, hotels and holiday cottages in Anglesy, consider staying in Anglesey which is 4 km (2 miles) away. Other places in and around Anglesy where you can find information about places to rent, and car hire include Holyhead which is 14 km (9 miles) away, Bangor, Porthmadog and Llandudno.











