Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 6 Sep 2026:
- Most powerful swell: Monday 7 Sep, 10PM (local time) - 8ft (2.4m), 7s period, SW swell with 511 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 2.4m 7s and forecast to arrive on Monday (Sep 07) at 10PM. Winds are predicted to be 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 Wednesday (Sep 09) at 7AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Mon 7th Sep) | 8ft (2.4m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here. Let me tell you how it's looking for the next couple of weeks.
To be honest, mate, it's a pretty grim picture for us here at Trearddur Bay (Holy Island). The entire 16-day forecast is a complete write-off. There's not a single session I'd recommend paddling out for. From the 6th of September all the way through to the 21st, every single check shows "poor surf conditions." That's a solid two weeks of nothing to get excited about.
The main problem is the wind. It's just relentless. We're looking at strong cross-onshore winds from the South and West nearly every day, and when it's not that, it's a fresh breeze blowing straight onshore. The swell is there, but it's a messy, lumpy, blown-out mess. For example, on the 16th of September, we've got a solid 8 ft of swell from the SW with a combined energy of 508 (moderate wave energy), but with a moderate cross-shore wind, it's just not going to hold together. A couple of days earlier, the 12th of September, has a near gale from the SSW at 34 mph, which is just pure kiting conditions, not for a surfboard.
The water temperature is sitting at 62°F, which is a touch warmer than normal for this time of year, but that's the only bit of good news. The swell is almost all short-period windswell, under 8 seconds, so there's no real power or shape to it.
Honestly, this is one of those stretches where the forecasts can change, and it tends not to stay this poor for long, but as it stands right now, save your wax and don't bother with the wetsuit. There's nothing here for us.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Mon night. Very mild (max 19°C on Sun afternoon, min 12°C on Mon night). Winds decreasing (strong winds from the SW on Mon night, light winds from the NW by Wed morning). | Days 5-7 Weather SummaryLight rain (total 6mm), mostly falling on Wed night. Very mild (max 18°C on Thu night, min 13°C on Wed night). Winds increasing (light winds from the SW on Fri afternoon, near gales from the SSW by Sat morning). | |||||||||||||||||||
Sun 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | ||||||||||||||
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 6 | SSW 6 | SW 14 | SSW 5 | SW 7 | WSW 6 | W 6 | NW 7 | SW 6 | SW 8 | SW 4 | SW 6 | SSW 6 | SW 6 | NW 5 | SW 6 | SSW 4 | SSW 5 | SW 6 | SW 6 |
Wave Graph  | ||||||||||||||||||||
 kJ | 181 | 159 | 33 | 59 | 428 | 181 | 239 | 411 | 10 | 9 | 32 | 237 | 176 | 106 | 43 | 19 | 13 | 109 | 77 | 42 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | cross-on | cross-on | cross-on | cross-on | cross | cross | cross-on | on | on | on | cross-on | cross | cross-on | cross-on | cross-on | on | cross-off |
High Tide | 7:01PM4.59m | 7:54AM4.65m | 8:23PM4.91m | 9:02AM4.96m | 9:21PM5.29m | 9:53AM5.26m | 10:08PM5.63m | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | 11:50AM5.61m | 00:04AM5.91m | |||||||
Low Tide | 1:25AM1.84m | 1:57PM1.96m | 2:38AM1.44m | 3:00PM1.61m | 3:33AM1.02m | 3:50PM1.24m | 4:19AM0.68m | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | 5:39AM0.42m | 5:49PM0.68m | ||||||||
 |  |  | | | |  |  | |  |  | | | | | | |  | | | |
 | — | — | 6:37 | — | — | 6:39 | — | — | 6:39 | — | — | 6:41 | — | — | 6:43 | — | — | 6:45 | — | — |
 | 7:57 | — | — | 7:53 | — | — | 7:52 | — | — | 7:50 | — | — | 7:46 | — | — | 7:45 | — | — | 7:42 | — |
mm | — | 1 | — | — | 4 | — | 1 | — | — | — | 1 | 2 | — | 1 | — | — | — | 2 | — | — |
Temp °C | 19 | 17 | 15 | 16 | 15 | 14 | 15 | 14 | 14 | 14 | 15 | 15 | 17 | 18 | 14 | 15 | 15 | 16 | 17 | 15 |
Feels °C | 12 | 13 | 11 | 11 | 6 | 6 | 7 | 5 | 9 | 11 | 10 | 9 | 13 | 14 | 10 | 13 | 7 | 7 | 12 | 13 |
Swell 1 Height (m) Direction Period (s) | SW 13 | — | SW 14 | WNW 4 | SW 12 | — | — | SW 6 | SW 6 | N 5 | N 4 | — | — | — | SW 6 | SW 6 | NNW 4 | — | SW 6 | SW 6 |
| kJ | 6 | — | 33 | 1 | 6 | — | — | 27 | 10 | 28 | 2 | — | — | — | 39 | 19 | 1 | — | 77 | 42 |
Swell 2 Height (m) Direction Period (s) | — | SW 17 | — | — | — | — | — | — | WSW 8 | SW 8 | — | — | — | — | — | NNW 4 | SW 8 | — | — | — |
| kJ | — | 11 | — | — | — | — | — | — | 6 | 9 | — | — | — | — | — | 12 | 2 | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | NW 4 | — | — | — | — | — | — | NW 4 | — | — | — |
| kJ | — | — | — | — | — | — | — | — | — | 3 | — | — | — | — | — | — | 1 | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 6 | SSW 6 | WSW 4 | SSW 5 | SW 7 | WSW 6 | W 6 | NW 7 | NW 6 | W 4 | SW 4 | SW 6 | SSW 6 | SW 6 | NW 5 | WNW 4 | SSW 4 | SSW 5 | — | NW 3 |
| kJ | 181 | 159 | 20 | 59 | 428 | 181 | 239 | 411 | 152 | 8 | 32 | 237 | 176 | 106 | 43 | 3 | 13 | 109 | — | 1 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 346 | 284 | 51 | 326 | 280 | 280 | 611 | 548 | 179 | 51 | 246 | 275 | 503 | 167 | 179 | 51 | 179 | 246 | 347 | 55 |
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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