Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 3 Sep 2026:
- Most powerful swell: Thursday 3 Sep, 10PM (local time) - 5.5ft (1.7m), 7s period, SW swell with 255 kJ wave energy.
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 1.7m 7s and forecast to arrive on Thursday (Sep 03) 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 Tuesday (Sep 08) at 7PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Thu 3rd Sep) | 5.5ft (1.7m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Right then, folks. Rusty here, and I’ve had a proper look at the charts for our little corner. I’ve got to be straight with you – it’s a grim outlook for Trearddur Bay on Holy Island. The whole 16-day window is basically one long dry spell.
Right from Thursday, September 3rd, it’s a write-off. We’ve got a sloppy 4ft to 5ft swell, but it’s getting battered by a stiff onshore wind, making a mess of things. That sets the tone for the next week and a half. The wind barely gives us a break, swinging from cross-on to onshore, and the waves are either too small or too chopped up. The combined wave energy is mostly weak, bouncing around 48 to 227, which is just nothing to get excited about. It’s just a lot of lumpy, unrideable slop. For a spot that’s a bit of a fair-weather wave anyway, this is tough.
There is one moment that almost makes you look twice. On Thursday, September 10th, the afternoon sees a solid 8ft swell from the SW with a period of 7 seconds, and the combined energy jumps right up to 612. But don’t be fooled. The wind is still doing its dirty work – a light cross-onshore breeze is enough to put a wind-chop on it, and the forecast is only calling it marginal at best. That size is also tipping into the ‘too big for beginners’ territory, so unless you’re a seasoned local paddling out into a messy, 8ft onshore lump, you’re giving it a miss. The crowds here are sometimes an issue, but honestly, I don’t think anyone is going to be paddling out for that.
The rest of the window is more of the same. The 11th and 12th of September offer a clean cross-off wind, which is a nice change, but the swell disappears. You’re looking at 3ft to 6ft of weak, short-period rubbish. By the time we get to the 14th and 15th, it’s flat. There’s a bit of glassy water, but the swell is just a memory – we’re talking 0.3ft to 2ft with no energy. It's a dead loss. The final week is looking just as poor, with a few days showing zero wave height.
So, the honest truth? There are no standouts here. None. For a wave that’s inconsistent at the best of times, this is a proper flat spell. The only thing that might interest a kiter is that 8ft day on the 10th, but for the surfer? It’s time to take up golf or check the forecasts for somewhere else. It can’t stay this bad forever, but this window is a write-off.
Rusty.
Short Range ForecastModerate rain (total 16mm), heaviest on Thu night. Very mild (max 18°C on Wed night, min 13°C on Fri night). Mainly strong winds. | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Mon afternoon. Warm (max 20°C on Sun afternoon, min 13°C on Mon night). Winds increasing (moderate winds from the S on Sat night, near gales from the SSW by Mon afternoon). | ||||||||||||||||||||
Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | |||||||||||||||
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 7 | SW 5 | SW 7 | WSW 5 | SW 5 | WNW 5 | NW 5 | SSW 3 | SSW 4 | SSW 5 | SSW 6 | SSW 6 | SW 6 | SSW 6 | SW 6 | WNW 6 | NW 6 | SW 6 | NW 5 | W 4 | SW 5 |
Wave Graph  | |||||||||||||||||||||
 kJ | 147 | 106 | 178 | 123 | 102 | 46 | 21 | 7 | 16 | 41 | 169 | 70 | 43 | 227 | 120 | 209 | 167 | 15 | 53 | 16 | 56 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | on | on | on | cross-on | cross-on | cross-on | cross | cross | on | on |
High Tide | 3:01PM5.01m | 3:30AM5.02m | 3:59PM4.75m | 4:41AM4.69m | 5:21PM4.55m | 6:18AM4.51m | 7:01PM4.59m | 7:54AM4.65m | 8:23PM4.91m | 9:02AM4.96m | 9:21PM5.29m | 9:53AM5.26m | 10:08PM5.63m | ||||||||
Low Tide | 8:51AM1.28m | 9:16PM1.51m | 9:47AM1.66m | 10:23PM1.82m | 10:59AM2.01m | 11:50PM1.99m | 12:31PM2.14m | 1:25AM1.84m | 1:57PM1.96m | 2:38AM1.44m | 3:00PM1.61m | 3:33AM1.02m | 3:50PM1.24m | ||||||||
 |  |  | |  |  | | |  | | | | | | | | | |  | |  | |
 | 6:30 | — | — | 6:31 | — | — | 6:33 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | 6:39 | — | — |
 | — | 8:04 | — | — | 8:01 | — | — | 7:59 | — | — | 7:57 | — | — | 7:53 | — | — | 7:52 | — | — | 7:50 | — |
mm | — | 3 | 13 | — | — | — | — | — | — | — | — | — | — | 2 | — | — | — | — | — | — | 2 |
Temp °C | 17 | 18 | 16 | 15 | 17 | 16 | 14 | 14 | 16 | 19 | 20 | 17 | 15 | 16 | 13 | 14 | 15 | 13 | 14 | 15 | 15 |
Feels °C | 13 | 14 | 11 | 8 | 11 | 10 | 12 | 10 | 11 | 12 | 15 | 12 | 10 | 7 | 3 | 5 | 6 | 5 | 9 | 9 | 9 |
Swell 1 Height (m) Direction Period (s) | SW 14 | SW 14 | NW 4 | SW 14 | SW 14 | SW 6 | NW 5 | NNW 4 | SW 13 | SW 13 | SW 13 | SSW 6 | NW 4 | — | SW 6 | — | SW 6 | SW 6 | SW 6 | NNW 5 | — |
| kJ | 8 | 8 | 3 | 8 | 8 | 36 | 21 | 2 | 7 | 7 | 6 | 70 | 8 | — | 120 | — | 58 | 15 | 5 | 7 | — |
Swell 2 Height (m) Direction Period (s) | — | — | SW 14 | — | SW 14 | SW 7 | SW 6 | WNW 4 | — | — | — | SW 12 | SW 13 | — | — | — | — | S 11 | — | SW 7 | — |
| kJ | — | — | 8 | — | 8 | 12 | 18 | 1 | — | — | — | 6 | 27 | — | — | — | — | 2 | — | 2 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SW 14 | SW 14 | SW 13 | SW 13 | — | — | W 16 | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | 8 | 7 | 7 | 7 | — | — | 5 | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SW 7 | SW 5 | SW 7 | WSW 5 | SW 5 | WNW 5 | — | SSW 3 | SSW 4 | SSW 5 | SSW 6 | WNW 4 | SW 6 | SSW 6 | WNW 4 | WNW 6 | NW 6 | NW 6 | NW 5 | W 4 | SW 5 |
| kJ | 147 | 106 | 178 | 123 | 102 | 46 | — | 6 | 16 | 41 | 169 | 11 | 43 | 227 | 26 | 209 | 167 | 110 | 53 | 16 | 56 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 288 | 514 | 167 | 348 | 548 | 179 | 51 | 246 | 179 | 321 | 292 | 280 | 246 | 584 | 174 | 838 | 514 | 326 | 285 | 246 | 280 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
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Information about the Trearddur Bay (Holy Island) Surf forecast
The above surf forecast table for Trearddur Bay (Holy Island) provides essential information for determining whether the surfing conditions will be good over the next 16 days. A general guide to surfing at Trearddur Bay (Holy Island) can be found by selecting the local surf guide option on the grey menu. Our Trearddur Bay (Holy Island) 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 (Trearddur Bay (Holy Island)) 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 Trearddur Bay (Holy Island) 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 Trearddur Bay (Holy Island), camping, hotels and holiday cottages in Anglesy, consider staying in Holyhead 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 Anglesey which is 7 km (4 miles) away, Bangor, Porthmadog and Llandudno.
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