
Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 12 Sep 2026:
- Best quality surf: Sunday 13 Sep, 7AM (local time) - 2.5ft (0.8m), 6s period, SSW swell with cross-offshore winds.
- Most powerful swell: Saturday 12 Sep, 10AM (local time) - 7ft (2.2m), 7s period, SW swell with 434 kJ wave energy.
- Next surfable swell (1★+): Sunday 13 Sep, 7AM (local time) - 2.5ft (0.8m), 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 Sunday (Sep 13) at 7AM. The primary swell is predicted to be 0.8m 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 2.2m 7s and forecast to arrive on Saturday (Sep 12) at 10AM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.6m 5s period and expected on Wednesday (Sep 16) at 4PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 7AM (Sun 13th Sep) | 2.5ft (0.8m) 6s |
| Best Surf | 7AM (Sun 13th Sep) | 2.5ft (0.8m) 6s |
| Most Powerful | 10AM (Sat 12th Sep) | 7ft (2.2m) 7s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Right then, folks. Rusty here. Let's have a look at what's on the cards for the next couple of weeks down at Cable Bay. I'll be straight with you, it's a tough stretch.
We've got a long, quiet start here. Don't expect much of anything for the first week. From Friday the 11th right through until the end of the week, the guidance is all showing “poor surf conditions.” The swell's tiny, the winds are onshore or messy, and the whole setup just isn't there. It’s going to be a dry spell for paddle surfing.
Things take a slight turn as we head into the second week. You can start getting your hopes up around Monday the 21st of September. The morning session sees a bit of a pulse. The combined energy lifts to a moderate 251, with a solid 6ft swell rolling in from the SW, with a decent 7-second period. It’s a bit of size, but it'll be a bit lumpy with a moderate cross-shore breeze. If you're looking for the pick of the fortnight, that Monday morning window is the standout, but it’s not perfect by any stretch.
Then, keep an eye on the weekend of the 26th of September. Saturday morning and afternoon both show a bit more promise. The swell bumps up to 6-6ft from the SW, with combined energy jumping to 229 and then 312. What makes this interesting is the light NW cross-shore wind. That's a combo that could clean it up nicely. It's still a fair bit of swell – over 5ft – so it might be a bit much for the beginners, but for those with a bit of experience, it could be worth a paddle. It's a long-range call, so consider it promising but not locked in yet.
Water temp is sitting at a "a touch warmer than normal" at 62°, which is nice for the time of year.
So, overall, it's a real waiting game. The first week is a write-off. Your best bets are the morning of Monday the 21st and the weekend of the 26th. Be patient, check the forecasts, and don't be afraid to have the kite gear ready if the wind gets too strong.
Rusty.
Short Range ForecastModerate rain (total 10mm), heaviest on Sat morning. Very mild (max 17°C on Sat afternoon, min 14°C on Fri night). Winds increasing (light winds from the S on Fri afternoon, strong winds from the SSW by Sat morning). | Days 5-7 Weather SummaryHeavy rain (total 20mm), heaviest during Mon afternoon. Very mild (max 17°C on Mon afternoon, min 12°C on Tue night). Winds increasing (light winds from the WNW on Mon night, strong winds from the SW by Wed night). | |||||||||||||||||||
Fri 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | Thursday 17 | ||||||||||||||
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 6 | SSW 4 | SW 7 | SW 7 | SW 6 | SW 6 | SW 6 | SSW 3 | SSW 4 | SSW 5 | SW 6 | SW 6 | SW 6 | NW 5 | NW 6 | W 4 | SW 5 | SW 6 | W 5 | WNW 5 |
Wave Graph | ||||||||||||||||||||
19 | 29 | 434 | 363 | 123 | 39 | 18 | 9 | 24 | 64 | 226 | 38 | 20 | 92 | 123 | 17 | 85 | 80 | 68 | 64 | |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross-on | on | on | on | cross-off | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross | cross | on | on | cross-on | cross-on | cross-on |
High Tide | 10:17PM4.51m | 10:42AM4.11m | 10:54PM4.52m | 11:16AM4.11m | 11:30PM4.39m | 11:50AM4.02m | 00:07AM4.16m | 12:24PM3.85m | 00:44AM3.84m | 1:00PM3.60m | 1:24AM3.48m | 1:40PM3.31m | 2:09AM3.11m | |||||||
Low Tide | 4:43PM-0.03m | 5:10AM-0.34m | 5:22PM-0.06m | 5:48AM-0.24m | 5:59PM0.01m | 6:23AM-0.01m | 6:35PM0.19m | 6:58AM0.30m | 7:12PM0.44m | 7:33AM0.66m | 7:49PM0.75m | 8:09AM1.03m | 8:30PM1.08m | |||||||
— | — | 6:45 | — | — | 6:47 | — | — | 6:48 | — | — | 6:50 | — | — | 6:52 | — | — | 6:54 | — | — | |
7:44 | — | — | 7:42 | — | — | 7:38 | — | — | 7:37 | — | — | 7:35 | — | — | 7:31 | — | — | 7:30 | — | |
mm | — | 1 | 8 | — | 1 | — | — | — | — | 6 | 10 | — | 1 | — | — | — | 2 | 1 | 1 | — |
Temp °C | 15 | 15 | 16 | 17 | 17 | 15 | 15 | 16 | 17 | 17 | 17 | 14 | 16 | 14 | 13 | 15 | 16 | 14 | 15 | 13 |
Feels °C | 12 | 12 | 10 | 15 | 16 | 14 | 14 | 13 | 15 | 13 | 12 | 9 | 12 | 8 | 7 | 10 | 10 | 7 | 8 | 5 |
Swell 1 Height (m) Direction Period (s) | SW 6 | — | — | — | SW 6 | SW 6 | SW 6 | — | — | — | S 12 | SW 6 | WNW 4 | SW 5 | SW 6 | NNW 5 | — | SW 6 | SW 7 | — |
19 | — | — | — | 123 | 39 | 18 | — | — | — | 3 | 38 | 12 | 4 | 1 | 21 | — | 80 | 54 | — | |
Swell 2 Height (m) Direction Period (s) | WNW 4 | — | — | — | — | — | N 4 | — | — | — | — | — | — | — | S 11 | — | — | — | — | — |
5 | — | — | — | — | — | 3 | — | — | — | — | — | — | — | 2 | — | — | — | — | — | |
Swell 3 Height (m) Direction Period (s) | N 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
3 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | — | SSW 4 | SW 7 | SW 7 | — | NNW 4 | — | SSW 3 | SSW 4 | SSW 5 | SW 6 | WNW 4 | SW 6 | NW 5 | NW 6 | W 4 | SW 5 | WNW 5 | W 5 | WNW 5 |
— | 29 | 434 | 363 | — | 4 | — | 9 | 24 | 64 | 226 | 30 | 20 | 92 | 123 | 17 | 85 | 69 | 68 | 64 | |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 44 | 269 | 261 | 308 | 244 | 45 | 150 | 179 | 256 | 287 | 261 | 261 | 603 | 339 | 187 | 261 | 591 | 1075 | 618 | 783 |
Best forecast wave conditions in Anglesy | ||||||||||||||||||||
Best forecast wave conditions in United Kingdom | ||||||||||||||||||||
Header Global | ||||||||||||||||||||
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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.











