Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 2 Sep 2026:
- Most powerful swell: Thursday 3 Sep, 1AM (local time) - 6ft (1.8m), 7s period, SW swell with 287 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 1.8m 7s and forecast to arrive on Thursday (Sep 03) at 1AM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.3m 5s period and expected on Saturday (Sep 05) at 10AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1AM (Thu 3rd Sep) | 6ft (1.8m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, it’s Rusty here. Let’s get honest about the next couple of weeks for Trearddur Bay (Holy Island). I’ve looked at the charts, and to be blunt, the outlook is a tough one. We’ve got a long, drawn-out run of poor surf stretching from now all the way to mid-September. The first real glimmer of something surfable doesn’t show up until the 17th.
Right now, we’re stuck in a rut. For the first several days, from the 2nd right through to the 14th, the swell energy is weak, often dropping below 100 (moderate wave energy when it does tick up) and the wind is just not cooperating. We’re seeing a lot of cross-onshore and onshore breezes from the south and southwest, up to 22 mph, making for lumpy, messy, and choppy conditions. The water temperature is about where you’d expect for this time of year, so nothing unusual there.
Things go completely flat for a few days around the 11th and 12th, with barely any energy to speak of. You’d have trouble getting a ride on a boogie board. That flat spell stretches into the middle of the month.
The only real standout – and I’m using the term loosely – is on Thursday, the 17th of September. We finally see a spike in energy. The swell comes up to 5 ft from the SW with a 6-second period, pushing the combined energy to 142 (moderate wave energy). More importantly, the wind goes light offshore from the NNW in the morning, which will clean things up. For a break that’s only fairly exposed and inconsistent at the best of times, this is our one shot. The waves will be surfable, but with a short period, don’t expect any barrels – just some fun, if a little weak, lines. It won’t be big enough to worry anyone, so beginners could have a crack, and crowds are possible here on a decent day.
Don’t hold your breath for anything before that. This is a long blank run for the area, so dust off the gear and be ready for the 17th.
Rusty.
Short Range ForecastModerate rain (total 15mm), heaviest on Thu night. Very mild (max 18°C on Wed night, min 13°C on Fri night). Winds decreasing (fresh winds from the S on Wed morning, light winds from the W by Thu night). | Days 4-6 Weather SummaryLight rain (total 4mm), mostly falling on Mon afternoon. Very mild (max 19°C on Sun afternoon, min 13°C on Sat morning). Winds increasing (light winds from the W on Sat morning, strong winds from the SSW by Mon afternoon). | ||||||||||||||||||||
Wednesday 2 | Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | Tuesday 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 5 | SSW 6 | SW 7 | SW 7 | SSW 6 | SSW 6 | W 5 | WSW 5 | WNW 5 | SW 6 | SW 6 | SSW 4 | SSW 4 | SSW 5 | SW 6 | SW 13 | SW 5 | WSW 5 | WSW 6 | WSW 6 | W 6 |
Wave Graph  | |||||||||||||||||||||
 kJ | 61 | 173 | 287 | 144 | 196 | 113 | 115 | 69 | 87 | 18 | 16 | 13 | 36 | 86 | 52 | 26 | 106 | 161 | 204 | 167 | 183 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | on | on | on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on | on | on | cross |
High Tide | 2:15PM5.23m | 2:36AM5.34m | 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 | ||||||||
Low Tide | 8:25PM1.22m | 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 | ||||||||
 |  |  | | |  | | |  | |  | | | | | | | |  | |  | |
 | 6:28 | — | — | 6:30 | — | — | 6:31 | — | — | 6:33 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — |
 | — | 8:06 | — | — | 8:04 | — | — | 8:01 | — | — | 7:59 | — | — | 7:57 | — | — | 7:53 | — | — | 7:52 | — |
mm | 5 | — | — | — | 1 | 9 | — | — | — | — | — | — | — | — | — | — | 4 | — | 1 | 1 | 1 |
Temp °C | 16 | 17 | 18 | 17 | 18 | 16 | 15 | 17 | 15 | 13 | 14 | 15 | 18 | 19 | 17 | 15 | 16 | 14 | 13 | 14 | 13 |
Feels °C | 10 | 13 | 14 | 12 | 14 | 12 | 8 | 11 | 8 | 10 | 10 | 10 | 10 | 13 | 13 | 11 | 8 | 5 | 3 | 4 | 2 |
Swell 1 Height (m) Direction Period (s) | S 16 | SW 16 | SW 15 | NW 4 | — | WNW 4 | SW 14 | SW 14 | SW 7 | SW 6 | NW 4 | SW 13 | SW 13 | SW 13 | SW 6 | SW 13 | — | SW 11 | — | — | — |
| kJ | 5 | 10 | 9 | 4 | — | 7 | 8 | 8 | 12 | 18 | 3 | 7 | 7 | 6 | 52 | 7 | — | 5 | — | — | — |
Swell 2 Height (m) Direction Period (s) | — | — | — | SW 14 | — | SW 14 | — | — | SW 14 | NNW 5 | N 5 | — | — | — | SW 12 | SW 13 | — | — | — | — | — |
| kJ | — | — | — | 8 | — | 8 | — | — | 8 | 5 | 2 | — | — | — | 6 | 26 | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SW 14 | — | — | — | SW 14 | SW 13 | — | — | — | W 15 | — | — | — | — | — | — |
| kJ | — | — | — | — | — | 8 | — | — | — | 7 | 7 | — | — | — | 5 | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 5 | SSW 6 | SW 7 | SW 7 | SSW 6 | SSW 6 | W 5 | WSW 5 | WNW 5 | WNW 4 | SW 6 | SSW 4 | SSW 4 | SSW 5 | — | WSW 3 | SW 5 | WSW 5 | WSW 6 | WSW 6 | W 6 |
| kJ | 61 | 173 | 287 | 144 | 196 | 113 | 115 | 69 | 87 | 12 | 16 | 13 | 36 | 86 | — | 10 | 106 | 161 | 204 | 167 | 183 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 246 | 249 | 252 | 315 | 288 | 503 | 167 | 179 | 527 | 179 | 192 | 235 | 163 | 275 | 189 | 279 | 51 | 348 | 326 | 51 | 208 |
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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