Surf Forecasts:
Cable Bay (Porth Trecastell) surf forecast from 4 Sep 2026:
- Most powerful swell: Thursday 10 Sep, 1AM (local time) - 8ft (2.5m), 7s period, SSW swell with 553 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 2.5m 7s and forecast to arrive on Thursday (Sep 10) at 1AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.5m 6s period and expected on Wednesday (Sep 09) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1AM (Thu 10th Sep) | 8ft (2.5m) 7s |
Table - best surf conditions forecast for Cable Bay (Porth Trecastell) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at the next 16 days for Cable Bay (Porth Trecastell). I’ll be straight with you – it’s a tough run. There’s no real standout, and for a good stretch we’re staring at a whole lot of nothing worth paddling out for.
The first recommendation doesn’t show up until Sunday the 13th of September. That means Friday the 4th right through to Saturday the 12th is basically a write-off. We’ve got a few days of messy, lumpy, cross-onshore junk in the 2 ft to 7 ft range, but with wind tearing it up and combined swell energy mostly weak to moderate (a few days hitting 366 on the 8th, but it’s a total mess). Not worth waxing the board for.
Now, Sunday the 13th of September morning is where we get our first real sniff. Swell comes in at 4 ft from the SW with a period of 5 seconds. Light breeze off the NNE and clean conditions. Combined energy is 68, so weak, but it’s clean. If you’re desperate, that morning window is the best we get early on. That afternoon picks up to 5 ft, same SW direction, but it goes cross-shore with just small ripples – still rideable.
Monday the 14th of September morning and afternoon both serve up a solid 8 ft from the SW with a 7-second period. Combined energy jumps to 539, which is strong. Problem is, it’s onshore wind from the SSW at 12-15 mph. That makes the surface poor. That’s a fairly heavy, lumpy wave – best left for experienced surfers only. Beginners stay far clear of this one.
After that, the swell drops off hard from Tuesday the 15th onward. Tiny bits of energy, nothing over 2 ft, and mostly with onshore or cross-onshore wind. Thursday the 17th and Friday the 18th of September go glassy or cross-off, but with swell at 0.3 ft to 0.7 ft, there’s just no push.
To sum it up: the only window that’s worth looking at is Sunday the 13th of September morning for clean, small waves. Monday the 14th is for experts only with big, messy swell. After that, it’s flat and calm for the rest of the run. Not our best stretch, but that’s how it goes sometimes.
Rusty.
Short Range ForecastModerate rain (total 15mm), heaviest on Thu night. Warm (max 20°C on Sun afternoon, min 13°C on Fri night). Mainly fresh winds. | Days 4-6 Weather SummaryLight rain (total 4mm), mostly falling on Mon night. Very mild (max 17°C on Sun night, min 12°C on Mon night). Mainly strong winds. | ||||||||||||||||||||
Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | |||||||||||||||
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) | WSW 5 | SW 6 | W 5 | W 5 | SW 6 | SSW 4 | SSW 5 | SSW 6 | SSW 6 | SW 14 | SW 5 | WSW 6 | W 6 | W 6 | WNW 6 | W 5 | SW 5 | SSW 7 | SW 7 | SW 7 | W 4 |
Wave Graph  | |||||||||||||||||||||
 kJ | 168 | 123 | 120 | 46 | 26 | 42 | 55 | 119 | 202 | 40 | 63 | 211 | 366 | 214 | 201 | 71 | 55 | 553 | 169 | 104 | 46 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | on | cross-on | on | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | on | cross |
High Tide | 2:44PM3.26m | 3:24AM3.18m | 4:06PM3.08m | 5:04AM3.02m | 5:48PM3.13m | 6:46AM3.12m | 7:12PM3.41m | 7:58AM3.37m | 8:11PM3.77m | 8:48AM3.63m | 8:58PM4.11m | 9:29AM3.86m | 9:39PM4.37m | ||||||||
Low Tide | 9:25AM1.02m | 9:57PM1.11m | 10:40AM1.25m | 11:26PM1.19m | 12:11PM1.26m | 00:57AM0.99m | 1:29PM1.03m | 2:07AM0.62m | 2:30PM0.70m | 3:02AM0.22m | 3:19PM0.38m | 3:49AM-0.10m | 4:02PM0.12m | ||||||||
 |  |  | | |  |  | |  | | | | |  | | | |  | |  | | |
 | 6:31 | — | — | 6:33 | — | — | 6:35 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | 6:41 | — | — |
 | — | 8:00 | — | — | 7:59 | — | — | 7:55 | — | — | 7:53 | — | — | 7:52 | — | — | 7:49 | — | — | 7:46 | — |
mm | — | — | — | — | — | 3 | — | — | — | — | — | 3 | — | 1 | — | — | — | 11 | — | 1 | 1 |
Temp °C | 16 | 17 | 16 | 14 | 14 | 15 | 18 | 20 | 17 | 15 | 16 | 16 | 14 | 15 | 14 | 14 | 15 | 16 | 17 | 17 | 16 |
Feels °C | 10 | 11 | 10 | 11 | 10 | 11 | 12 | 15 | 13 | 12 | 11 | 8 | 7 | 8 | 8 | 8 | 10 | 12 | 14 | 13 | 11 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | SW 14 | NNW 6 | WNW 4 | SW 13 | SW 13 | SW 13 | SW 12 | SW 14 | SW 13 | — | — | — | N 13 | NNW 6 | NW 4 | — | — | SW 7 | SW 7 |
| kJ | 8 | 8 | 8 | 6 | 3 | 7 | 7 | 6 | 6 | 33 | 44 | — | — | — | 3 | 18 | 4 | — | — | 104 | 25 |
Swell 2 Height (m) Direction Period (s) | — | SW 14 | — | SW 14 | NNW 5 | — | — | — | — | — | — | — | — | — | — | — | NNW 5 | — | — | — | — |
| kJ | — | 8 | — | 7 | 5 | — | — | — | — | — | — | — | — | — | — | — | 5 | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | SW 14 | SW 13 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | 7 | 7 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | WSW 5 | SW 6 | W 5 | W 5 | SW 6 | SSW 4 | SSW 5 | SSW 6 | SSW 6 | WSW 4 | SW 5 | WSW 6 | W 6 | W 6 | WNW 6 | W 5 | SW 5 | SSW 7 | SW 7 | NW 4 | W 4 |
| kJ | 168 | 123 | 120 | 46 | 26 | 42 | 55 | 119 | 202 | 40 | 63 | 211 | 366 | 214 | 201 | 71 | 55 | 553 | 169 | 3 | 46 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 297 | 506 | 173 | 185 | 244 | 179 | 231 | 341 | 283 | 44 | 261 | 167 | 541 | 541 | 338 | 381 | 283 | 262 | 44 | 541 | 338 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
FREE! Surf-Forecast.com widget for your website
The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Cable Bay (Porth Trecastell) surf forecast. Simply grab the html code snippet that we provide and paste it into your own site. You can choose your preferred language and metric/imperial units for the surf forecast feed to suit users of your site. Click here to get the code.
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.
Nearest