
Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 12 Jul 2026:
- Most powerful swell: Friday 17 Jul, 7AM (local time) - 1.5ft (0.4m), 7s period, SSW swell with 21 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 0.4m 7s and forecast to arrive on Friday (Jul 17) at 7AM. Winds are predicted to be offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.5m 6s period and expected on Saturday (Jul 18) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 7AM (Fri 17th Jul) | 1.5ft (0.4m) 7s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
Alright, Rusty here. Let's have a look at what's cookin' at Cable Bay.
Honestly, it's a pretty grim stretch ahead. The next couple of weeks are looking like a big fat zero for any decent surf. We're staring down the barrel of a long, flat spell. From Sunday the 12th through to Saturday the 25th of July, the bay is basically asleep. We're talking nothing but tiny, dribbly leftovers that won't break a foot. The combined energy is barely a whisper, with readings like 1 in the weak range, and it barely gets into double figures. It's a real shame, because the wind is often offshore from the NE, but with no swell to work with, it's a waste of good conditions.
Now, there is a flicker of life way out on the horizon. Things start to get interesting on Sunday the 26th of July. We see a pulse of swell arriving, with the combined energy jumping to 164 on Sunday morning, then 268 by the afternoon. That's a solid, moderate wave energy event. But the wind is a messy cross-onshore, so while the swell is there at 5 ft to 6 ft from the SSW, it's going to be a choppy, blown-out mess. Not worth paddling out for.
The real standout, and the only window worth even thinking about, is Monday the 27th of July. The swell is pumping up to 8 ft from the SSW, with a period of 8 seconds, and the combined energy is a very strong 843. That's proper power. Now, that wave height is pushing into expert territory, especially at a beach break. The wind is light and cross-shore from the NW, which is a huge positive. It'll be a lot cleaner than the day before. However, the period is short, so it will be a bit of a lumpy, possibly closed-out affair at the beach. This setup might actually be more interesting for the kite crew than for paddle surfers, given the size and the onshore angle. The water temp is logged at 62°F, which is about a touch warmer than normal for the time of year, but that small comfort won't help you much when you're getting smashed.
So, to sum it up: a long, flat drought until the very end of the forecast. The only real chance for a wave is on Monday the 27th of July, but it's a big, powerful, and likely unruly one for experts only. The rest of the month is a write-off for Cable Bay.
Rusty.
Short Range ForecastMostly dry. Warm (max 25°C on Sun afternoon, min 15°C on Sun night). Mainly fresh winds. | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Thu afternoon. Warm (max 24°C on Wed afternoon, min 15°C on Fri night). Wind will be generally light. | ||||||||||||||||||||
Sun 12 | Monday 13 | Tuesday 14 | Wednesday 15 | Thursday 16 | Friday 17 | Saturday 18 | |||||||||||||||
PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | |
Swell Height Map | |||||||||||||||||||||
Wave Height (m) Direction Period (s) | NE 4 | NE 5 | SE 4 | S 19 | S 15 | S 18 | SW 18 | SW 14 | SW 16 | SW 16 | SSW 6 | SW 14 | SW 14 | SW 8 | SSW 7 | SSW 7 | SW 7 | SSW 6 | SSW 6 | SSW 6 | S 11 |
Wave Graph | |||||||||||||||||||||
0 | 0 | 1 | 7 | 4 | 6 | 12 | 7 | 10 | 10 | 4 | 8 | 8 | 15 | 21 | 18 | 11 | 8 | 8 | 3 | 2 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | off | off | off | off | off | off | off | off | off | off | off | cross-off | cross-off | cross-off | off | off | cross-off | cross-off | cross-off | off | cross |
High Tide | 8:18PM3.75m | 8:48AM3.79m | 9:12PM4.02m | 9:43AM3.93m | 10:03PM4.26m | 10:35AM4.00m | 10:51PM4.43m | 11:24AM3.99m | 11:39PM4.50m | 12:11PM3.90m | 00:25AM4.44m | 12:58PM3.76m | 1:12AM4.25m | ||||||||
Low Tide | 3:21AM0.38m | 3:45PM0.34m | 4:14AM0.05m | 4:35PM0.16m | 5:04AM-0.20m | 5:21PM0.05m | 5:52AM-0.33m | 6:06PM0.03m | 6:39AM-0.31m | 6:51PM0.12m | 7:25AM-0.16m | 7:35PM0.30m | 8:10AM0.10m | ||||||||
— | — | 5:05 | — | — | 5:07 | — | — | 5:07 | — | — | 5:09 | — | — | 5:11 | — | — | 5:11 | — | — | 5:13 | |
— | 9:40 | — | — | 9:39 | — | — | 9:38 | — | — | 9:37 | — | — | 9:37 | — | — | 9:36 | — | — | 9:34 | 9:32 | |
mm | — | — | — | — | — | — | — | — | — | — | — | 1 | 2 | — | — | — | — | — | — | — | — |
Temp °C | 25 | 23 | 19 | 21 | 19 | 20 | 23 | 21 | 23 | 24 | 23 | 21 | 21 | 20 | 19 | 18 | 16 | 20 | 20 | 19 | 18 |
Feels °C | 21 | 20 | 13 | 15 | 14 | 16 | 18 | 15 | 21 | 20 | 20 | 20 | 21 | 20 | 15 | 14 | 14 | 16 | 17 | 18 | 15 |
Swell 1 Height (m) Direction Period (s) | — | — | SE 4 | S 19 | S 15 | S 18 | SW 18 | S 7 | S 6 | SW 6 | NE 5 | SSW 6 | NNE 4 | SW 8 | SSW 7 | SSW 7 | SW 7 | SSW 6 | SSW 6 | SSW 6 | SW 6 |
— | — | 1 | 7 | 4 | 6 | 12 | 1 | 1 | 2 | 8 | 4 | 3 | 15 | 21 | 18 | 11 | 8 | 8 | 3 | 1 | |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | — | SW 14 | SW 16 | SW 16 | N 5 | SW 14 | SSW 6 | NNE 4 | NE 4 | — | SW 12 | S 11 | S 11 | S 11 | S 11 |
— | — | — | — | — | — | — | 7 | 10 | 10 | 4 | 8 | 3 | 3 | 1 | — | 6 | 2 | 2 | 2 | 2 | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | W 14 | — | — | S 13 | S 13 | SSW 6 | — | SW 14 | SW 6 | S 12 | SW 12 | — | — | — | — | — |
— | — | — | — | — | 4 | — | — | 3 | 3 | 4 | — | 8 | 1 | 3 | 6 | — | — | — | — | — | |
Wind waves Height (m) Direction Period (s) | NE 4 | NE 5 | NE 4 | NNE 4 | NE 4 | NE 4 | NNE 4 | NE 5 | NE 5 | NE 4 | ESE 3 | NE 4 | N 4 | — | — | — | N 3 | N 5 | NNW 5 | N 6 | NNW 6 |
22 | 25 | 31 | 32 | 18 | 20 | 28 | 26 | 14 | 19 | 1 | 5 | 1 | — | — | — | 3 | 23 | 35 | 194 | 80 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 306 | 306 | 420 | 301 | 284 | 178 | 158 | 294 | 353 | 211 | 356 | 221 | 158 | 211 | 329 | 329 | 178 | 352 | 542 | 53 | 118 |
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.











