Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 8 Aug 2026:
- Most powerful swell: Saturday 8 Aug, 4AM (local time) - 2ft (0.6m), 4s period, SSW swell with 12 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 0.6m 4s and forecast to arrive on Saturday (Aug 08) at 4AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 2s period and expected on Tuesday (Aug 11) at 4AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4AM (Sat 8th Aug) | 2ft (0.6m) 4s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Alright, Rusty here. Gotta call it as it is: Cable Bay (Porth Trecastell) is looking flat and grim for a solid stretch. We’ve got a gap of several days with no surf worth paddling for right from the start.
The first time you’ll see anything rideable is Wednesday morning, August 19th. A small swell at 4ft from the SW, with a combined swell energy of (114), which is moderate. The wind is light and cross-offshore from the N, so the surface will be clean. It’s surfable but nothing to write home about. The water is a touch warmer than usual for this time of year at 63°.
Thursday morning August 20th has a tiny 2ft SW swell with light offshore wind again, but the energy is low at (54). Clean but knee-high.
The rest of the run into late August is tiny. Most days show 0.3ft or less with combined energies in the single digits. A few glassy moments, like Tuesday afternoon August 11th and Sunday morning August 16th, but there’s no swell to push. It’s dead calm.
If you really want a surf, the cleanest and biggest day is Wednesday morning August 19th, but it’s not a standout. The second week is quiet – just small pulses that won’t get you out of bed. For an exposed SW spot like Cable Bay, we need a proper SW groundswell, and this forecast just doesn’t have it. With swell this small and energy this low, it’s more of a kite day than a paddle day. Hang tight.
Rusty.
Short Range ForecastMostly dry. Very mild (max 19°C on Sun afternoon, min 14°C on Fri night). Wind will be generally light. | Days 5-7 Weather SummaryMostly dry. Warm (max 27°C on Wed afternoon, min 16°C on Mon night). Wind will be generally light. | |||||||||||||||||||
Fri 7 | Saturday 8 | Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | ||||||||||||||
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) | S 12 | SSW 4 | SSW 4 | SSW 4 | SW 4 | S 12 | SW 12 | SW 3 | SW 6 | SSW 6 | SW 7 | SW 6 | SW 6 | S 11 | SSW 4 | SSW 4 | SSW 4 | SW 4 | SSW 3 | SW 4 |
Wave Graph  | ||||||||||||||||||||
 kJ | 3 | 12 | 7 | 9 | 11 | 3 | 6 | 1 | 1 | 3 | 2 | 2 | 1 | 3 | 5 | 6 | 10 | 4 | 4 | 9 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross-on | cross-on | on | cross-on | on | on | cross | cross-off | cross-off | off | cross-on | glassy | cross-off | cross-on | cross-on | cross-on | on | cross-on | cross-off |
High Tide | 4:28PM3.12m | 5:06AM3.20m | 5:53PM3.16m | 6:34AM3.25m | 7:10PM3.38m | 7:48AM3.43m | 8:14PM3.71m | 8:49AM3.66m | 9:07PM4.05m | 9:40AM3.86m | 9:54PM4.35m | 10:25AM4.00m | 10:38PM4.54m | |||||||
Low Tide | 11:32PM1.22m | 12:19PM1.13m | 1:01AM1.07m | 1:38PM0.97m | 2:14AM0.73m | 2:42PM0.68m | 3:13AM0.33m | 3:34PM0.38m | 4:04AM-0.04m | 4:20PM0.13m | 4:50AM-0.29m | 5:04PM-0.02m | ||||||||
 |  |  | | | | | | | |  | | | |  | | | | | | |
 | — | — | 5:45 | — | — | 5:47 | — | — | 5:48 | — | — | 5:50 | — | — | 5:52 | — | — | 5:52 | — | — |
 | — | 9:01 | — | — | 9:00 | — | 8:58 | — | — | 8:57 | — | — | 8:54 | — | — | 8:52 | — | — | 8:50 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 15 | 16 | 17 | 16 | 18 | 19 | 17 | 16 | 17 | 16 | 21 | 24 | 23 | 23 | 27 | 21 | 19 | 21 | 21 |
Feels °C | 12 | 12 | 12 | 13 | 13 | 17 | 17 | 16 | 13 | 14 | 12 | 19 | 23 | 21 | 20 | 23 | 19 | 20 | 21 | 21 |
Swell 1 Height (m) Direction Period (s) | WNW 3 | SW 12 | SW 11 | S 11 | SW 7 | SW 6 | SW 6 | SW 3 | SW 4 | SSW 6 | SW 7 | SW 6 | SW 6 | SW 6 | SW 12 | SW 10 | SW 9 | WNW 3 | SW 8 | SW 4 |
| kJ | 1 | 5 | 5 | 2 | 2 | 2 | 1 | 1 | 1 | 3 | 2 | 2 | 1 | 1 | 5 | 4 | 3 | 1 | 3 | 9 |
Swell 2 Height (m) Direction Period (s) | S 12 | W 12 | — | — | S 11 | S 12 | — | SW 6 | SW 6 | SW 8 | — | — | — | — | S 6 | S 12 | W 6 | SW 8 | SW 10 | SW 7 |
| kJ | 3 | 3 | — | — | 2 | 3 | — | 1 | 1 | 3 | — | — | — | — | 1 | 3 | 1 | 3 | 4 | 2 |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | SW 12 | — | — | — | — | — | — | S 11 | S 12 | — | — | SW 11 | — | S 11 |
| kJ | — | — | — | — | — | — | 6 | — | — | — | — | — | — | 3 | 3 | — | — | 4 | — | 2 |
Wind waves Height (m) Direction Period (s) | SW 2 | SSW 4 | SSW 4 | SSW 4 | SW 4 | SW 3 | — | — | — | N 3 | — | — | — | — | SSW 4 | SSW 4 | SSW 4 | SW 4 | SSW 3 | — |
| kJ | 2 | 12 | 7 | 9 | 11 | 2 | — | — | — | 1 | — | — | — | — | 4 | 6 | 10 | 4 | 4 | — |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 282 | 256 | 256 | 256 | 261 | 373 | 393 | 287 | 261 | 285 | 256 | 277 | 307 | 233 | 296 | 179 | 172 | 185 | 412 | 185 |
Best forecast wave conditions in Anglesy | ||||||||||||||||||||
Best forecast wave conditions in United Kingdom | ||||||||||||||||||||
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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.
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