Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 13 Aug 2026:
- Most powerful swell: Wednesday 19 Aug, 7AM (local time) - 5.5ft (1.7m), 6s period, WSW swell with 163 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 1.7m 6s and forecast to arrive on Wednesday (Aug 19) at 7AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 6s period and expected on Thursday (Aug 20) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 7AM (Wed 19th Aug) | 5.5ft (1.7m) 6s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Alright crew, Rusty here. Let's be straight with you: the next couple of weeks are looking pretty grim for a proper surf. We've got a long, flat spell ahead, so if you're jonesing for a wave, you might wanna take up fishing or something. We're looking at a serious dry spell, with barely a ripple for the next week and a half.
The first, and really only, time we see any sort of pulse is mid-next week. Tuesday the 18th sees a tiny bit of energy, but it's crossed up and messy, with a weak 3ft swell from the southwest at 6 seconds. The energy's still weak, coming in at 69. Not worth getting wet for. It gets slightly more interesting on Wednesday the 19th morning, with the swell bumping up to 4ft from the northwest at 5 seconds, and the energy reading a moderate 104. But it's a cross-onshore breeze, making it choppy and a bit of a mess. That’s not going to be pretty.
By that afternoon, the swell drops right back off and we are back to nothing. From the 20th through the 25th, we're looking at a long stretch of flatness. There’s some glassy conditions on the morning of the 22nd, but there's no swell to go with it. A tease, that’s all.
The only thing that changes toward the end of the run is the wind, which swings offshore from the east and northeast from the 24th onwards. It's clean, but it's blowing over a totally flat ocean. The swell energy is super weak, with values in the single digits. There’s a tiny uptick on Thursday the 27th, with a small 2-3ft swell from the south and SSW. It’s offshore and clean, but the swell is small and it’s a beach break. It's just not enough to get excited about.
So, honestly, there are no standouts here. The whole 16-day window is a bust. With the water temp at 64°, which is a touch warmer than normal for this time of year, you’d think the ocean would want to give us something. But it’s just flat. If it stays like this, it might be more interesting for the kite surfers than for us paddle surfers.
Hang loose, or don't. There's nothing to hang loose on. This is Rusty, signing off.
Short Range ForecastMostly dry. Warm (max 22°C on Thu afternoon, min 13°C on Sat night). Wind will be generally light. | Days 4-6 Weather SummaryLight rain (total 4mm), mostly falling on Tue morning. Very mild (max 18°C on Mon afternoon, min 14°C on Sun morning). Wind will be generally light. | ||||||||||||||||||||
Thursday 13 | Friday 14 | Saturday 15 | Sunday 16 | Monday 17 | Tuesday 18 | Wednesday 19 | |||||||||||||||
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 3 | SW 3 | SW 4 | SW 4 | SW 4 | SW 6 | W 8 | SW 6 | SW 7 | N 4 | N 4 | SW 2 | SW 3 | NW 3 | SSW 3 | SW 6 | SW 5 | WSW 5 | WSW 6 | SW 6 | NW 4 |
Wave Graph  | |||||||||||||||||||||
 kJ | 5 | 4 | 16 | 5 | 3 | 1 | 1 | 2 | 2 | 0 | 0 | 1 | 2 | 3 | 6 | 50 | 49 | 78 | 143 | 51 | 39 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-on | on | cross-off | cross-off | cross-off | cross-off | off | glassy | cross-on | cross-on | cross-on | cross | on | cross-on | cross-on | cross-on | cross-on | on | cross-on |
High Tide | 10:25AM4.00m | 10:38PM4.54m | 11:07AM4.05m | 11:19PM4.59m | 11:46AM4.02m | 00:00AM4.50m | 12:25PM3.91m | 00:40AM4.27m | 1:04PM3.73m | 1:21AM3.95m | 1:44PM3.51m | 2:05AM3.58m | 2:29PM3.25m | 2:56AM3.21m | |||||||
Low Tide | 5:04PM-0.02m | 5:34AM-0.40m | 5:45PM-0.06m | 6:15AM-0.35m | 6:25PM0.02m | 6:55AM-0.16m | 7:05PM0.20m | 7:34AM0.15m | 7:45PM0.46m | 8:13AM0.53m | 8:25PM0.77m | 8:54AM0.92m | 9:10PM1.10m | ||||||||
 | |  |  | |  | |  | | | | | | |  |  | | | | |  | |
 | 5:52 | — | — | 5:54 | — | — | 5:56 | — | — | 5:58 | — | — | 6:00 | — | — | 6:01 | — | — | 6:03 | — | — |
 | — | 8:50 | — | — | 8:47 | — | — | 8:45 | — | — | 8:44 | — | — | 8:42 | — | — | 8:39 | — | — | 8:37 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 4 | — | — | — | — | 3 |
Temp °C | 21 | 22 | 20 | 18 | 17 | 16 | 14 | 15 | 14 | 15 | 15 | 15 | 17 | 18 | 17 | 17 | 18 | 17 | 15 | 16 | 16 |
Feels °C | 20 | 22 | 19 | 19 | 14 | 13 | 9 | 11 | 11 | 12 | 13 | 13 | 16 | 18 | 16 | 14 | 15 | 14 | 10 | 11 | 10 |
Swell 1 Height (m) Direction Period (s) | SW 8 | SW 8 | SW 8 | SW 4 | SW 4 | SW 6 | SW 6 | SW 6 | — | N 4 | N 4 | — | SW 3 | SSW 3 | — | — | — | — | SW 16 | SW 6 | SW 6 |
| kJ | 3 | 2 | 2 | 5 | 3 | 1 | 1 | 2 | — | 3 | 1 | — | 2 | 1 | — | — | — | — | 10 | 51 | 16 |
Swell 2 Height (m) Direction Period (s) | SW 11 | SW 11 | S 11 | WNW 3 | — | — | W 8 | — | SW 7 | — | — | — | — | — | — | — | — | — | — | S 15 | SW 16 |
| kJ | 5 | 4 | 2 | 1 | — | — | 1 | — | 2 | — | — | — | — | — | — | — | — | — | — | 5 | 10 |
Swell 3 Height (m) Direction Period (s) | — | S 11 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | SW 15 | — |
| kJ | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | 9 | — |
Wind waves Height (m) Direction Period (s) | SW 3 | SW 3 | SW 4 | — | N 3 | N 4 | NNW 5 | NNW 5 | — | — | — | SW 2 | — | NW 3 | SSW 3 | SW 6 | SW 5 | WSW 5 | WSW 6 | NW 5 | NW 4 |
| kJ | 2 | 2 | 16 | — | 6 | 19 | 37 | 22 | — | — | — | 1 | — | 3 | 6 | 50 | 49 | 78 | 143 | 23 | 39 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 172 | 302 | 172 | 185 | 541 | 187 | 389 | 579 | 261 | 256 | 259 | 297 | 258 | 297 | 285 | 286 | 44 | 173 | 541 | 504 | 316 |
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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