Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 2 Aug 2026:
- Most powerful swell: Tuesday 4 Aug, 10PM (local time) - 6ft (1.8m), 6s period, SSW swell with 254 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 1.8m 6s and forecast to arrive on Tuesday (Aug 04) 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 Thursday (Aug 06) at 7AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Tue 4th Aug) | 6ft (1.8m) 6s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Alright, grab a seat, let’s talk about Cable Bay (Porth Trecastell). Straight up—this is a tough one. The next couple of weeks are looking pretty grim for any decent surf here. The water is sitting at 62°F, which is a touch warmer than normal for this time of year, but that’s about the only bright spot.
We’re looking at a long stretch of nothing. From now, right through the first week of August, the swell is tiny and weak. Sunday morning kicks off with a measly 1 ft from the SSW, period a pathetic 4 seconds, and the combined energy is a pitiful 4. It’s just not happening. The wind is glassy for a moment on Sunday morning, but there’s no wave to ride. That pattern holds through the start of the week—wave heights barely scraping 1 ft, periods short, and energy values stuck in the single digits or low teens. It’s all cross-on or onshore wind, keeping things choppy or messy.
There’s a small bump mid-week, Tuesday the 4th, with the swell pushing up to 4 ft, but it’s coming from the S and SSW, with a period of only 4 to 5 seconds. The energy finally climbs to 90, but with a fresh cross-onshore wind at 19 mph, it’s lumpy, choppy, and poor. Wednesday morning the 5th sees a bit more energy at 113, but again, cross-onshore winds and a 4 ft swell from the SW with a 7-second period. It’s just not clean.
The pattern of weak, short-period swells and unfriendly wind continues day after day. There’s a gap here where nothing really offers a good window. The energy values remain low, mostly under 100, and the wind never really settles into a solid offshore. The 14th of August shows a flicker of hope—Friday morning, 3 ft from the SSW, a 6-second period, and a light cross-onshore breeze. The energy is 57, and it’s rated as “marginal.” Even then, it’s not worth paddling out for.
The best of a very bad bunch looks like Sunday the 16th of August. We’ve got a 5 ft swell from the SW, a 6-second period, and energy of 155. It’s still cross-onshore in the morning, but the wind is only a gentle breeze. By the afternoon, the wind backs off to a light onshore at 6 mph, and the swell holds at 5 ft with energy of 172. The waves will be there, but the period is short, and the wind is onshore. It’s not going to be clean, but it might be the only time you’ll actually get a few rides. For the more experienced, it could be a little messy fun, but beginners will find it too big and sloppy.
Honestly, this is a rough run. If you’re desperate for a paddle, maybe the 16th is your best bet, but don’t expect much. The rest of the 16-day window is a write-off.
Rusty
Short Range ForecastLight rain (total 4mm), mostly falling on Mon night. Warm (max 22°C on Mon morning, min 14°C on Mon night). Winds increasing (calm on Sun morning, fresh winds from the SSW by Tue afternoon). | Days 4-6 Weather SummaryLight rain (total 3mm), mostly falling on Wed morning. Very mild (max 18°C on Fri afternoon, min 13°C on Wed night). Winds decreasing (fresh winds from the W on Wed night, light winds from the S by Thu night). | ||||||||||||||||||||
Sunday 2 | Monday 3 | Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | |||||||||||||||
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) | SSW 4 | SW 9 | W 10 | SW 9 | SW 8 | SW 8 | S 4 | SSW 5 | SSW 6 | SW 7 | SW 7 | NW 6 | SW 6 | WSW 4 | SW 4 | SSW 4 | SSW 4 | SW 5 | SW 6 | SW 6 | SW 6 |
Wave Graph  | |||||||||||||||||||||
 kJ | 3 | 3 | 3 | 3 | 11 | 10 | 30 | 90 | 253 | 113 | 164 | 138 | 9 | 10 | 6 | 3 | 15 | 36 | 38 | 16 | 8 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | glassy | cross-off | off | cross-on | cross-on | cross-off | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | on | on | cross | cross-on | on | cross-on |
High Tide | 12:20PM3.64m | 00:32AM4.05m | 12:54PM3.59m | 1:07AM3.94m | 1:32PM3.51m | 1:48AM3.77m | 2:18PM3.37m | 2:39AM3.55m | 3:15PM3.22m | 3:44AM3.33m | 4:28PM3.12m | 5:06AM3.20m | 5:53PM3.16m | ||||||||
Low Tide | 7:04PM0.48m | 7:33AM0.34m | 7:41PM0.62m | 8:12AM0.50m | 8:22PM0.79m | 8:55AM0.70m | 9:10PM0.99m | 9:47AM0.92m | 10:11PM1.16m | 10:55AM1.10m | 11:32PM1.22m | 12:19PM1.13m | 1:01AM1.07m | ||||||||
 | |  | | |  | |  | |  | | |  | | | | | | | | | |
 | 5:35 | — | — | 5:37 | — | — | 5:37 | — | — | 5:39 | — | — | 5:41 | — | — | 5:43 | — | — | 5:45 | — | — |
 | — | — | 9:12 | — | — | 9:09 | — | — | 9:07 | — | — | 9:06 | — | — | 9:04 | — | — | 9:01 | — | — | 9:00 |
mm | — | — | — | — | — | 4 | — | — | — | 2 | 1 | — | — | — | — | — | — | — | — | — | — |
Temp °C | 17 | 17 | 17 | 22 | 19 | 17 | 19 | 19 | 17 | 16 | 16 | 15 | 14 | 15 | 16 | 17 | 18 | 16 | 16 | 17 | 16 |
Feels °C | 15 | 15 | 13 | 20 | 16 | 15 | 16 | 14 | 13 | 15 | 12 | 9 | 9 | 12 | 13 | 15 | 15 | 14 | 14 | 14 | 14 |
Swell 1 Height (m) Direction Period (s) | — | — | SW 8 | NNE 4 | SW 8 | SW 8 | SW 8 | — | — | — | S 13 | SW 7 | SW 6 | NNW 6 | NNW 5 | — | S 12 | SW 5 | SW 6 | SW 6 | SW 6 |
| kJ | — | — | 3 | 3 | 11 | 10 | 9 | — | — | — | 3 | 52 | 9 | 35 | 5 | — | 3 | 36 | 38 | 16 | 8 |
Swell 2 Height (m) Direction Period (s) | W 8 | SW 9 | SW 9 | SW 9 | S 4 | — | NE 4 | — | — | — | — | S 13 | S 13 | S 12 | SW 6 | — | — | SW 12 | SW 11 | S 11 | — |
| kJ | 1 | 3 | 3 | 3 | 1 | — | 1 | — | — | — | — | 3 | 3 | 3 | 1 | — | — | 5 | 5 | 2 | — |
Swell 3 Height (m) Direction Period (s) | — | — | W 10 | — | NE 4 | — | — | — | — | — | — | — | — | W 12 | SW 12 | S 5 | — | — | — | — | — |
| kJ | — | — | 2 | — | 1 | — | — | — | — | — | — | — | — | 3 | 6 | 1 | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 4 | — | NNE 3 | SSE 3 | — | — | S 4 | SSW 5 | SSW 6 | SW 7 | SW 7 | NW 6 | NW 6 | WSW 4 | SW 4 | SSW 4 | SSW 4 | — | WNW 4 | NW 3 | WNW 3 |
| kJ | 3 | — | 7 | 2 | — | — | 30 | 90 | 253 | 113 | 164 | 138 | 156 | 10 | 6 | 3 | 15 | — | 8 | 3 | 2 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 256 | 256 | 158 | 179 | 185 | 181 | 272 | 277 | 277 | 96 | 44 | 173 | 299 | 272 | 272 | 256 | 256 | 150 | 185 | 258 | 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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