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Trearddur Bay (Holy Island) Surf Forecast
/ Wales – Anglesy (10 surf breaks) /
Surf Forecasts:
Trearddur Bay (Holy Island) surfForecast / Wales – Anglesy / UK
12 Day Weather and Surf, issued 12 am Sunday 14 Sep 2025 BST
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 12 days are 4.5m 9s and forecast to arrive on Monday (Sep 15) at 10AM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.4m 6s period and expected on Tuesday (Sep 16) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10AM (Mon 15th Sep) | 15ft (4.5m) 9s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 12 days.
Short Range Forecast Moderate rain (total 15mm), heaviest on Mon morning. Very mild (max 16°C on Sun afternoon, min 13°C on Sun morning). Winds increasing (light winds from the SW on Sat night, gales from the WSW by Mon morning). | Days 3-6 Weather Summary Moderate rain (total 16mm), heaviest on Tue night. Very mild (max 17°C on Wed morning, min 13°C on Tue night). Winds decreasing (near gales from the SW on Wed afternoon, light winds from the SSW by Fri morning). | |||||||||||||||||||||
Sunday 14 | Monday 15 | Tuesday 16 | Wednesday 17 | Thursday 18 | Friday 19 | Sat 20 | ||||||||||||||||
| Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | Night | AM | PM | ||
Rating (10 max) | ||||||||||||||||||||||
Swell Height Map |  |  |  |  |  |  |  |  | ||||||||||||||
| Wave Height (m) & direction (?) | ||||||||||||||||||||||
| Period(s) (?) | 7 | 5 | 7 | 8 | 9 | 7 | 7 | 6 | 6 | 6 | 7 | 8 | 6 | 8 | 7 | 7 | 6 | 7 | 7 | 6 | 6 | |
Wave (?)Graph  | ||||||||||||||||||||||
 kJ (?) | 132 | 66 | 460 | 1135 | 3286 | 1131 | 725 | 332 | 126 | 112 | 800 | 746 | 261 | 515 | 509 | 432 | 60 | 47 | 21 | 12 | 13 | |
Wind (km/h) | ||||||||||||||||||||||
| Wind State (?) onshore cross-onshore cross-shore cross-offshore offshore glassy | cross- on | cross- on | cross- on | on | on | cross- on | cross- on | cross- on | on | on | on | on | on | on | on | cross- on | cross- on | cross- on | cross- off | cross- on | cross- on | |
High Tide / height (m) | 3:27AM 5.14 | 3:55PM 4.83 | 4:39AM 4.73 | 5:16PM 4.59 | 6:17AM 4.50 | 6:58PM 4.60 | 7:53AM 4.61 | 8:19PM 4.88 | 8:59AM 4.87 | 9:16PM 5.21 | 9:47AM 5.10 | 10:00PM 5.47 | 10:26AM 5.27 | |||||||||
Low Tide / height (m) | 9:40AM 1.64 | 10:17PM 1.72 | 10:53AM 2.07 | 11:45PM 1.96 | 12:26PM 2.26 | 1:21AM 1.88 | 1:53PM 2.12 | 2:34AM 1.57 | 2:55PM 1.82 | 3:28AM 1.24 | 3:42PM 1.51 | 4:10AM 0.98 | 4:20PM 1.25 | |||||||||
Sunday 14 | Monday 15 | Tuesday 16 | Wednesday 17 | Thursday 18 | Friday 19 | Sat 20 | ||||||||||||||||
| Sunrise | - | 6:48 | - | - | 6:50 | - | - | 6:52 | - | - | 6:54 | - | - | 6:56 | - | - | 6:56 | - | - | 6:58 | - | |
| Sunset | - | - | 7:37 | - | - | 7:35 | - | - | 7:32 | - | - | 7:30 | - | - | 7:28 | - | - | 7:24 | - | - | 7:22 | |
 |  |  | | | |  |  |  |  | | | | |  | | | | | | | ||
Rain (mm) | 1 | 2 | 3 | 4 | 3 | 2 | - | - | - | 15 | - | - | - | - | - | 1 | - | - | - | 2 | 6 | |
| Temp. °C | 14 | 14 | 16 | 15 | 14 | 15 | 14 | 14 | 15 | 16 | 17 | 16 | 15 | 15 | 15 | 16 | 14 | 15 | 17 | 17 | 18 | |
| Feels °C (?) | 8 | 7 | 7 | 6 | 2 | 5 | 3 | 7 | 9 | 9 | 8 | 5 | 6 | 9 | 9 | 11 | 12 | 12 | 13 | 10 | 13 | |
- Map Icons:
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Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)- Wind Speed (km/h)
Recent Eyeball Surf Reports for Wales - Anglesy
Cross-on wind has become light (light winds from the WSW at Mona 17 km from Trearddur Bay (Holy Island)). 0.7m 8s swell from the SW with a 0.4m 4s local chop from the WNW and a 0.3m 8s swell from the SW. 3 swells combining to make bigger set waves.
17 km away, 52 min ago
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The surf report / weather widget below is available to embed on third party websites free of charge and provides a summary of our Trearddur Bay (Holy Island) 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 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 12 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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