Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 5 Sep 2026:
- Most powerful swell: Thursday 10 Sep, 10PM (local time) - 5.5ft (1.7m), 6s period, SSW swell with 202 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 6s and forecast to arrive on Thursday (Sep 10) 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 0.9m 5s period and expected on Saturday (Sep 12) at 4AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10PM (Thu 10th Sep) | 5.5ft (1.7m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s cooking for Trearddur Bay on Holy Island. I’ve got to be straight with you – the next couple of weeks look pretty grim for a proper session. The first real shot of anything rideable doesn't show up until Thursday, the 17th of September, and even then, it’s not going to win any awards.
We’ve got a long, dry spell before that. From now all the way through to Wednesday the 16th, it’s just a whole lot of nothing. There are a few pulses of swell, but the wind is a nightmare – mostly strong cross-onshore or onshore, making everything messy and lumpy. The combined wave energy barely gets into triple digits most days, and anything that does arrive is either short period windswell or tiny. It’s just not worth paddling out for.
The only standout, and I mean the *only* one, comes on Thursday morning, the 17th of September. Trearddur Bay (Holy Island) will see a clean little pulse from the west. Swell heights are around 5 ft, with a period of 6 seconds, so it’s a short-period windswell, but the wind is light offshore from the NE. That offshore flow will clean up the surface nicely. The combined wave energy will be a moderate 169, so there’s a bit of push to it. It’s a beginner-friendly break, so the size is manageable, but don’t expect any world-class barrels. It’s a rare glimmer of clean conditions in an otherwise bleak outlook. The water temperature is 63°, which is a touch warmer than normal for this time of year.
After that, it fades off again. The following Friday and Saturday see a bit more swell, but the wind swings back onshore or cross-onshore, bringing back the choppy conditions. So, if you’re desperate for a surf, make that Thursday morning your target. It’s the only real chance you’ve got.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Mon night. Very mild (max 19°C on Sun afternoon, min 13°C on Mon night). Winds increasing (light winds from the W on Sun night, strong winds from the W by Tue morning). | Days 5-7 Weather SummaryLight rain (total 4mm), mostly falling on Thu night. Very mild (max 17°C on Thu night, min 13°C on Tue night). Winds decreasing (strong winds from the W on Tue afternoon, light winds from the WSW by Wed night). | |||||||||||||||||||
Sat 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | ||||||||||||||
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 6 | SSW 4 | SSW 5 | SSW 6 | SW 6 | SW 14 | SW 5 | WSW 6 | WSW 5 | W 5 | NW 6 | NW 6 | WSW 4 | NW 4 | SW 4 | SSW 6 | SW 6 | SW 6 | SW 6 | NW 4 |
Wave Graph  | ||||||||||||||||||||
 kJ | 16 | 24 | 111 | 139 | 137 | 33 | 91 | 119 | 117 | 134 | 171 | 131 | 14 | 6 | 24 | 138 | 152 | 37 | 30 | 37 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | cross-on | cross-on | cross-on | on | on | on | cross-on | cross-on | cross-on | cross | cross | cross-on | on | cross-on | cross-on | on | cross | cross-on | cross |
High Tide | 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 | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | |||||||
Low Tide | 11:50PM1.99m | 12:31PM2.14m | 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 | ||||||||
 |  |  | |  |  | |  | | |  |  | | | | | | | | | |
 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | 6:39 | — | — | 6:41 | — | — | 6:43 | — | — |
 | 7:59 | — | — | 7:57 | — | — | 7:53 | — | — | 7:52 | — | — | 7:50 | — | — | 7:46 | — | — | 7:45 | — |
mm | — | 1 | 1 | — | — | — | 1 | 3 | — | — | — | — | — | — | — | — | 4 | — | — | — |
Temp °C | 14 | 15 | 17 | 19 | 17 | 15 | 16 | 15 | 14 | 15 | 14 | 14 | 15 | 16 | 15 | 16 | 17 | 14 | 16 | 15 |
Feels °C | 10 | 9 | 10 | 12 | 13 | 12 | 9 | 12 | 5 | 7 | 6 | 9 | 11 | 13 | 11 | 10 | 11 | 7 | 11 | 9 |
Swell 1 Height (m) Direction Period (s) | NW 4 | SW 13 | SW 13 | SW 13 | SW 12 | SW 14 | WNW 4 | SW 12 | — | — | SW 6 | SW 6 | NNW 5 | NW 4 | — | — | — | SW 6 | SW 6 | SW 7 |
| kJ | 4 | 7 | 7 | 6 | 6 | 33 | 1 | 6 | — | — | 26 | 11 | 32 | 6 | — | — | — | 37 | 30 | 21 |
Swell 2 Height (m) Direction Period (s) | NNW 5 | — | — | — | — | — | — | — | — | — | S 11 | — | SW 9 | SW 7 | — | — | — | — | — | — |
| kJ | 2 | — | — | — | — | — | — | — | — | — | 2 | — | 3 | 2 | — | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | SW 13 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 7 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SW 6 | SSW 4 | SSW 5 | SSW 6 | SW 6 | WSW 4 | SW 5 | WSW 6 | WSW 5 | W 5 | NW 6 | NW 6 | WSW 4 | SW 4 | SW 4 | SSW 6 | SW 6 | WNW 4 | WNW 4 | NW 4 |
| kJ | 16 | 24 | 111 | 139 | 137 | 25 | 91 | 119 | 117 | 134 | 171 | 131 | 14 | 4 | 24 | 138 | 152 | 24 | 25 | 37 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 235 | 186 | 238 | 446 | 210 | 51 | 511 | 280 | 548 | 548 | 346 | 326 | 273 | 179 | 238 | 275 | 323 | 548 | 548 | 179 |
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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