Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 30 Jul 2026:
- Most powerful swell: Friday 31 Jul, 10PM (local time) - 2ft (0.6m), 4s period, SW swell with 16 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 Friday (Jul 31) at 10PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 4s period and expected on Monday (Aug 03) at 7PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Fri 31st Jul) | 2ft (0.6m) 4s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Right then, let’s take a look at what’s on offer here at Cable Bay. I’ve got to be honest with you, the forecast is a tough one. We’re looking at a 16-day window, but there’s a big, flat gap right at the start. From Thursday the 30th of July right through to the 14th of August, the surf is rated as poor across the board. The swell heights are tiny, mostly between 0.3 ft and 2 ft, with a short, weak period. The combined swell energy is very low, barely reaching double digits (14) at its best, and often just a 1 or 2. It’s a real struggle.
For the first week, the wind is a mess – cross, cross-on, and onshore – making what little wave there is a choppy, bumpy mess. There’s a brief moment on the morning of Sunday the 2nd of August where it goes glassy, but with a swell of just 0.7 ft, you’d be floating. The afternoons and mornings do see some clean offshore winds from the 3rd of August onward, with the wind coming from the ENE, but the swell just isn’t there to back it up. The water temperature is about average for the time of year, so no surprises there.
There isn’t a single standout in this entire period. Not one. The combination of no swell energy and persistent poor conditions means there’s nothing worth paddling out for. This is one of those times where the forecast is just a blank run. If you’re desperate, you’d be looking at the very end of the forecast, around the 14th of August, where there’s a hint of a 1 ft swell from the SW with a clean cross-off wind, but we’re talking about a week and a half away and it’s still tiny. Honestly, for the foreseeable future, you’re better off finding something else to do.
Rusty.
Short Range ForecastMostly dry. Very mild (max 17°C on Fri night, min 13°C on Thu night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 9mm), mostly falling on Mon night. Warm (max 20°C on Sun afternoon, min 13°C on Mon night). Winds increasing (calm on Sun morning, fresh winds from the ENE by Mon afternoon). | ||||||||||||||||||||
Thursday 30 | Friday 31 | Saturday 1 | Sunday 2 | Monday 3 | Tuesday 4 | Wednesday 5 | |||||||||||||||
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) | WNW 4 | NW 3 | WSW 3 | W 4 | SW 3 | SSW 5 | WNW 4 | NW 3 | SW 4 | SSW 4 | W 9 | SW 10 | SW 9 | SW 9 | SW 8 | SW 8 | SSW 7 | SSW 7 | SSW 7 | SSW 7 | SW 13 |
Wave Graph  | |||||||||||||||||||||
 kJ | 9 | 3 | 3 | 10 | 3 | 14 | 9 | 3 | 5 | 1 | 2 | 4 | 3 | 12 | 10 | 9 | 5 | 5 | 4 | 4 | 7 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross | cross | on | cross-on | on | cross | cross-on | on | cross-on | glassy | off | cross-off | off | off | off | off | off | cross-off | glassy | glassy | off |
High Tide | 10:49AM3.58m | 11:01PM4.02m | 11:19AM3.63m | 11:31PM4.09m | 11:49AM3.65m | 00:00AM4.10m | 12:20PM3.64m | 00:32AM4.05m | 12:54PM3.59m | 1:07AM3.94m | 1:32PM3.51m | 1:48AM3.77m | 2:18PM3.37m | 2:39AM3.55m | |||||||
Low Tide | 5:13AM0.35m | 5:20PM0.43m | 5:48AM0.25m | 5:54PM0.38m | 6:22AM0.21m | 6:28PM0.40m | 6:57AM0.24m | 7:04PM0.48m | 7:33AM0.34m | 7:41PM0.62m | 8:12AM0.50m | 8:22PM0.79m | 8:55AM0.70m | 9:10PM0.99m | |||||||
 | |  | | | | | |  | |  | |  |  |  | | |  | | | | |
 | 5:30 | — | — | 5:31 | — | — | 5:33 | — | — | 5:35 | — | — | 5:37 | — | — | 5:37 | — | — | 5:39 | — | — |
 | — | — | 9:16 | — | — | 9:15 | — | — | 9:13 | — | — | 9:12 | — | — | 9:09 | — | — | 9:07 | — | — | 9:06 |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | 1 | 7 | 1 | — | 1 | 2 | 2 | 1 |
Temp °C | 15 | 16 | 16 | 14 | 16 | 17 | 14 | 15 | 15 | 19 | 20 | 16 | 17 | 19 | 15 | 16 | 15 | 14 | 14 | 14 | 13 |
Feels °C | 11 | 14 | 14 | 10 | 12 | 14 | 11 | 12 | 13 | 17 | 17 | 13 | 13 | 15 | 11 | 13 | 11 | 11 | 14 | 14 | 8 |
Swell 1 Height (m) Direction Period (s) | SW 4 | NW 3 | — | SW 4 | NW 3 | SSW 5 | SW 5 | NW 3 | — | SSW 4 | — | SW 10 | NNW 3 | SW 9 | SW 8 | SW 8 | SSW 7 | SSW 7 | SSW 7 | SSW 7 | SW 6 |
| kJ | 5 | 3 | — | 3 | 2 | 14 | 7 | 3 | — | 1 | — | 4 | 2 | 12 | 10 | 9 | 5 | 5 | 4 | 4 | 2 |
Swell 2 Height (m) Direction Period (s) | — | SSW 5 | — | — | — | — | — | — | W 9 | — | W 9 | SW 8 | SW 9 | — | — | — | — | — | — | SE 4 | — |
| kJ | — | 2 | — | — | — | — | — | — | 2 | — | 2 | 3 | 3 | — | — | — | — | — | — | 1 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | S 13 | SW 13 |
| kJ | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 3 | 7 |
Wind waves Height (m) Direction Period (s) | WNW 4 | — | WSW 3 | W 4 | SW 3 | WNW 2 | WNW 4 | SSW 5 | SW 4 | — | NNE 3 | NNE 3 | NE 3 | NE 3 | NE 4 | NE 4 | NE 4 | ENE 3 | ENE 4 | ENE 3 | NE 5 |
| kJ | 9 | — | 3 | 10 | 3 | 1 | 9 | 2 | 5 | — | 3 | 2 | 2 | 7 | 11 | 6 | 11 | 3 | 9 | 3 | 5 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 541 | 580 | 256 | 302 | 363 | 287 | 390 | 363 | 256 | 259 | 179 | 172 | 150 | 211 | 180 | 296 | 283 | 284 | 326 | 283 | 282 |
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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