
Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 3 Sep 2026:
- Most powerful swell: Thursday 3 Sep, 10PM (local time) - 5.5ft (1.7m), 7s period, SW swell with 255 kJ wave energy.
Best Forecast Surf Conditions for Cable Bay (Porth Trecastell) this week:
The most powerful waves expected at Cable Bay (Porth Trecastell) in the next 16 days are 1.7m 7s and forecast to arrive on Thursday (Sep 03) at 10PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.6m 6s period and expected on Tuesday (Sep 08) at 7PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Thu 3rd Sep) | 5.5ft (1.7m) 7s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
G'day, Rusty here with a look at what's cookin' at Cable Bay (Porth Trecastell) for the next couple of weeks. I gotta be straight with ya, it's a pretty bleak run for most of the period, so don't get your hopes up too high.
The story for the first week and a half is largely about wind and messy conditions. A solid SW groundswell rolls in at times, but with strong onshore and cross-onshore winds, it just doesn't come together. For the next seven days, from Thursday the 3rd right through to Wednesday the 9th, it's a real struggle. Swell heights bob around from 2ft to 6ft, but that's paired with a constant strong breeze. The wave energy is generally moderate, but the wind tears it all apart. We're seeing mostly "Fresh cross-onshore and lumpy" or similar comments in the data. You'd be fighting a losing battle out there.
Now, there is a tiny glimmer. On the morning of Thursday, the 10th, it's still ugly with a 7ft swell and strong wind. But look at the afternoon of the 10th. The swell builds to a solid 8ft from the SW, and the wind drops to a light breeze. The combined energy hits a strong 612. The swell period is a short 7 seconds though. It's still listed as marginal, not a classic. For the experienced lads on a big board, there might be something to chase, but it'll be a grunty, lumpy beast. That’s the only day you could even call surfable.
After that, from the 11th to the 13th, the wind finally goes offshore from the north, giving us some clean, cross-off conditions on the morning of the 11th with a 4ft swell. But the energy is weak to moderate (120 and lower), and the waves are small and weak. It's clean, but it's not really worth paddling out for. The weekend of the 12th and 13th is just moderate cross-shore chop and small waves. Then we hit another lull. From Monday the 14th through to Friday the 18th, the swell drops right out. The sea goes glassy a few times, but there's just no energy. The waves are tiny, with heights mostly under 2ft. On the 18th, we finally get some light offshore wind, but with a tiny 1ft WNW swell, it's only for the super mini-mals.
The real standout, if you want to call it that, is the Thursday afternoon on the 10th. That's the one shot at a powerful, big wave, but it's a rough one. For the majority of this forecast, you're better off leaving the board in the car. The water temp is about average for this time of year, so no wild surprises there. It’s a bit of a washout, folks.
Rusty
Short Range ForecastModerate rain (total 17mm), heaviest on Thu night. Very mild (max 18°C on Wed night, min 14°C on Thu night). Winds decreasing (fresh winds from the WSW on Fri morning, light winds from the WSW by Sat morning). | Days 4-6 Weather SummaryLight rain (total 4mm), mostly falling on Mon afternoon. Warm (max 21°C on Sun afternoon, min 12°C on Mon night). Winds increasing (light winds from the SSE on Sat night, strong winds from the SSW by Mon afternoon). | ||||||||||||||||||||
Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | |||||||||||||||
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) | SW 7 | SW 5 | SW 7 | WSW 5 | SW 5 | WNW 5 | NW 5 | SSW 3 | SSW 4 | SSW 5 | SSW 6 | SSW 6 | SW 6 | SSW 6 | SW 6 | WNW 6 | NW 6 | SW 6 | NW 5 | W 4 | SW 5 |
Wave Graph | |||||||||||||||||||||
147 | 106 | 178 | 123 | 102 | 46 | 21 | 7 | 16 | 41 | 169 | 70 | 43 | 227 | 120 | 209 | 167 | 15 | 53 | 16 | 56 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | on | on | on | cross-on | cross-on | cross-on | cross | cross | on | cross-on |
High Tide | 1:47PM3.51m | 2:14AM3.50m | 2:44PM3.26m | 3:24AM3.18m | 4:06PM3.08m | 5:04AM3.02m | 5:48PM3.13m | 6:46AM3.12m | 7:12PM3.41m | 7:58AM3.37m | 8:11PM3.77m | 8:48AM3.63m | 8:58PM4.11m | ||||||||
Low Tide | 8:28AM0.72m | 8:50PM0.88m | 9:25AM1.02m | 9:57PM1.11m | 10:40AM1.25m | 11:26PM1.19m | 12:11PM1.26m | 00:57AM0.99m | 1:29PM1.03m | 2:07AM0.62m | 2:30PM0.70m | 3:02AM0.22m | 3:19PM0.38m | 3:49AM-0.10m | |||||||
6:30 | — | — | 6:31 | — | — | 6:33 | — | — | 6:35 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | |
— | 8:02 | — | — | 8:00 | — | — | 7:59 | — | — | 7:55 | — | — | 7:53 | — | — | 7:52 | — | — | 7:49 | — | |
mm | — | 3 | 14 | — | — | — | — | — | — | — | — | 1 | — | 3 | — | — | — | 1 | — | — | 2 |
Temp °C | 17 | 17 | 16 | 15 | 17 | 16 | 14 | 14 | 16 | 19 | 21 | 18 | 15 | 16 | 13 | 14 | 15 | 13 | 14 | 15 | 15 |
Feels °C | 14 | 13 | 12 | 8 | 11 | 11 | 12 | 10 | 12 | 12 | 16 | 15 | 11 | 8 | 4 | 6 | 7 | 6 | 10 | 10 | 9 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | NW 4 | SW 14 | SW 14 | SW 6 | NW 5 | NNW 4 | SW 13 | SW 13 | SW 13 | SSW 6 | NW 4 | — | SW 6 | — | SW 6 | SW 6 | SW 6 | NNW 5 | — |
8 | 8 | 3 | 8 | 8 | 36 | 21 | 2 | 7 | 7 | 6 | 70 | 8 | — | 120 | — | 58 | 15 | 5 | 7 | — | |
Swell 2 Height (m) Direction Period (s) | — | — | SW 14 | — | SW 14 | SW 7 | SW 6 | WNW 4 | — | — | — | SW 12 | SW 13 | — | — | — | — | S 11 | — | SW 7 | — |
— | — | 8 | — | 8 | 12 | 18 | 1 | — | — | — | 6 | 27 | — | — | — | — | 2 | — | 2 | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SW 14 | SW 14 | SW 13 | SW 13 | — | — | W 16 | — | — | — | — | — | — | — | — | — |
— | — | — | — | — | 8 | 7 | 7 | 7 | — | — | 5 | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | SW 7 | SW 5 | SW 7 | WSW 5 | SW 5 | WNW 5 | — | SSW 3 | SSW 4 | SSW 5 | SSW 6 | WNW 4 | SW 6 | SSW 6 | WNW 4 | WNW 6 | NW 6 | NW 6 | NW 5 | W 4 | SW 5 |
147 | 106 | 178 | 123 | 102 | 46 | — | 6 | 16 | 41 | 169 | 11 | 43 | 227 | 26 | 209 | 167 | 110 | 53 | 16 | 56 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 290 | 506 | 168 | 338 | 541 | 173 | 44 | 256 | 172 | 322 | 302 | 277 | 256 | 591 | 167 | 830 | 506 | 329 | 284 | 256 | 277 |
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.










