Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 23 Aug 2026:
- Best quality surf: Thursday 27 Aug, 7PM (local time) - 2.5ft (0.8m), 8s period, SSW swell with glassy winds.
- Most powerful swell: Saturday 29 Aug, 4AM (local time) - 7ft (2.1m), 6s period, W swell with 301 kJ wave energy.
- Next surfable swell (1★+): Thursday 27 Aug, 7PM (local time) - 2.5ft (0.8m), 8s 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 Thursday (Aug 27) at 7PM. The primary swell is predicted to be 0.8m and 8s period. The wind is predicted to be glassy as the swell arrives.
The most powerful waves expected at Cable Bay (Porth Trecastell) in the next 16 days are 2.1m 6s and forecast to arrive on Saturday (Aug 29) 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 0.9m 4s period and expected on Tuesday (Aug 25) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 7PM (Thu 27th Aug) | 2.5ft (0.8m) 8s |
| Best Surf | 7PM (Thu 27th Aug) | 2.5ft (0.8m) 8s |
| Most Powerful | 4AM (Sat 29th Aug) | 7ft (2.1m) 6s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s be straight with you: the next 16 days at Cable Bay (Porth Trecastrell) are looking like a write-off. I’ve scanned the charts and there’s just nothing worth paddling out for. We’re looking at a long dry spell for any decent waves.
The whole forecast period is a ghost town for surf. The swell is tiny, mostly 0.3 ft, and when it does try to push past that, the wind is all over the shop. The water temp is sitting at a very unusual 64° – that’s much warmer than normal for this time of year, so you’d be warm, but you’d be floating on a lake.
We start Sunday morning, the 23rd of August, with a tiny 0.3 ft swell from the SW and a cross-offshore breeze. The combined energy is a measly 16 (weak energy). It’s a clean-looking surface, but there’s no push in the water. Monday morning the 24th is glassy, but the swell is still just 0.3 ft. It’s heartbreaking.
The only faint glimmer comes on Thursday the 27th of August, when the afternoon shows a 3 ft swell from the SSW, period 7 seconds, with the combined energy hitting 61 (still weak). The wind is onshore from the SW though, and the surf is described as marginal. This is not a session to get excited about.
Friday the 28th sees the swell bump up to 4 ft, but it’s a short-period, wind-affected mess with a 5-second period and cross-on winds. The energy is 77 (weak). By Saturday the 29th, the swell hits 6 ft from the W with a combined energy of 206 (moderate wave energy), but it’s accompanied by a 22 mph cross-on wind. The wave comment is “poor surf conditions” and it’s lumpy. This is kite-surfing territory, not paddle surfing.
The rest of the run into September is a sad story of tiny, blown-out, or onshore junk. On the 4th of September, the swell tries to get to 4 ft again, but with a 25 mph onshore wind, it’s a no-go.
So, what’s the best on offer? Honestly, there isn’t one. This is a blank run for the area. Cable Bay is an exposed SW spot, and it’s just not getting the love. The forecast confidence is high for the near term because it’s so consistently bad. For a place that’s fairly consistent, this is a rough patch. Don’t hold your breath; forecasts can change, but for now, the board stays in the van.
Rusty.
Short Range ForecastLight rain (total 4mm), mostly falling on Tue night. Warm (max 23°C on Tue afternoon, min 14°C on Sun morning). Winds increasing (calm on Mon morning, fresh winds from the E by Tue night). | Days 4-6 Weather SummaryHeavy rain (total 20mm), heaviest during Thu morning. Warm (max 21°C on Wed afternoon, min 15°C on Wed night). Winds increasing (calm on Wed afternoon, fresh winds from the W by Fri night). | ||||||||||||||||||||
Sunday 23 | Monday 24 | Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | |||||||||||||||
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 14 | SW 14 | SW 14 | SW 14 | SW 13 | SW 13 | SW 13 | SW 13 | SSW 8 | SSW 8 | SSW 8 | SSW 5 | SSW 7 | SSW 7 | SSW 8 | SSW 5 | SSW 5 | W 6 | W 6 | SW 7 | WNW 5 |
Wave Graph | |||||||||||||||||||||
8 | 7 | 7 | 8 | 7 | 7 | 7 | 7 | 7 | 13 | 12 | 5 | 15 | 61 | 161 | 77 | 77 | 266 | 206 | 85 | 55 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | cross-off | off | glassy | cross-off | cross-off | cross-off | off | cross-off | cross-off | glassy | cross-off | cross-off | on | cross-on | cross-on | on | cross-on | cross-on | cross-on | glassy |
High Tide | 7:32PM3.02m | 8:05AM2.99m | 8:24PM3.28m | 8:49AM3.20m | 9:03PM3.55m | 9:25AM3.40m | 9:35PM3.81m | 9:55AM3.58m | 10:04PM4.02m | 10:23AM3.73m | 10:32PM4.18m | 10:51AM3.84m | 11:00PM4.28m | ||||||||
Low Tide | 1:41PM1.46m | 2:17AM1.25m | 2:33PM1.20m | 3:02AM0.96m | 3:12PM0.93m | 3:39AM0.68m | 3:47PM0.67m | 4:13AM0.41m | 4:20PM0.46m | 4:45AM0.20m | 4:53PM0.30m | 5:18AM0.06m | 5:26PM0.21m | ||||||||
6:11 | — | — | 6:11 | — | — | 6:13 | — | — | 6:16 | — | — | 6:16 | — | — | 6:18 | — | — | 6:20 | — | — | |
— | 8:29 | — | — | 8:27 | — | — | 8:23 | — | — | 8:22 | — | — | 8:20 | — | — | 8:16 | — | — | 8:15 | — | |
mm | — | — | — | — | — | — | — | — | 4 | — | 2 | 1 | 7 | — | — | — | 7 | 3 | 2 | 1 | 1 |
Temp °C | 15 | 16 | 17 | 19 | 20 | 19 | 21 | 23 | 20 | 20 | 21 | 19 | 19 | 19 | 17 | 17 | 15 | 16 | 16 | 16 | 17 |
Feels °C | 12 | 13 | 14 | 17 | 18 | 15 | 17 | 19 | 13 | 20 | 22 | 19 | 17 | 18 | 16 | 14 | 13 | 13 | 11 | 12 | 15 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | SW 13 | SW 10 | SW 9 | SW 13 | SW 13 | SW 13 | SSW 8 | SSE 4 | SSW 8 | SSW 5 | SSW 4 | SSW 7 | — | — | — | — | — | SW 7 | SW 6 |
8 | 7 | 7 | 4 | 3 | 7 | 7 | 7 | 7 | 4 | 12 | 4 | 3 | 61 | — | — | — | — | — | 85 | 31 | |
Swell 2 Height (m) Direction Period (s) | SW 14 | — | SW 14 | SW 14 | SW 13 | SW 9 | SW 8 | SW 8 | S 13 | NE 5 | NNE 5 | SSW 7 | SSW 7 | NE 4 | — | — | — | — | — | — | — |
8 | — | 7 | 8 | 7 | 3 | 3 | 3 | 3 | 4 | 2 | 5 | 5 | 1 | — | — | — | — | — | — | — | |
Swell 3 Height (m) Direction Period (s) | — | — | SW 14 | — | — | — | N 5 | — | — | SSW 8 | SW 6 | S 12 | NE 4 | — | — | — | — | — | — | — | — |
— | — | 7 | — | — | — | 1 | — | — | 13 | 1 | 3 | 1 | — | — | — | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | N 4 | N 4 | NNE 2 | — | — | E 3 | ENE 5 | NE 5 | ENE 4 | SSE 4 | SSW 5 | NE 2 | SSW 7 | — | SSW 8 | SSW 5 | SSW 5 | W 6 | W 6 | WNW 5 | WNW 5 |
6 | 2 | 1 | — | — | 7 | 14 | 20 | 27 | 11 | 7 | 1 | 15 | — | 161 | 77 | 77 | 266 | 206 | 29 | 55 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 260 | 211 | 158 | 256 | 259 | 256 | 258 | 258 | 233 | 233 | 260 | 211 | 179 | 44 | 44 | 221 | 212 | 279 | 282 | 506 | 0 |
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.











