Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 8 Sep 2026:
- Most powerful swell: Thursday 10 Sep, 4PM (local time) - 7ft (2.2m), 7s period, SW swell with 400 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 2.2m 7s and forecast to arrive on Thursday (Sep 10) at 4PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.8m 6s period and expected on Wednesday (Sep 09) at 1AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Thu 10th Sep) | 7ft (2.2m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s get straight into it for this stretch of the coast.
Honestly, looking at the next couple of weeks, it’s a pretty grim picture. There are no good surf options on offer for the entire 16-day window. Every single day is showing poor surf conditions. It’s not just a few days, it’s a solid blank run from start to finish.
The Overall Pattern
We start with Trearddur Bay (Holy Island) , and from Tuesday the 8th to Wednesday the 23rd of September, it’s a write-off. The combined swell energy is mostly weak, with values often below 100, and only a couple of moderate bumps mid-week that still come with horrible wind. For example, on Thursday the 10th afternoon, we see a moderate energy reading (400) with a 7 ft swell from the SW, but it’s accompanied by a strong cross-onshore wind at 25 mph, making it messy and unsurfable. That pattern repeats itself: a little bump in swell, but the wind is always cross, cross-on, or onshore, and the water gets chopped up.
The water temperature is sitting at 62° on the 8th, which is a touch warmer than normal for this time of year, but honestly, with the conditions so poor, it’s hard to get excited about that.
Day by Day
There is no standout day. Not one. The wind is never clean, the swell never aligns. On the 13th, Sunday morning, we get a light cross-offshore breeze and it looks clean, but the swell is a pathetic 2 ft with a weak 39 energy reading – just not enough to bother with.
Even later in the forecast, around the 21st and 22nd, when the swell period stretches out to 13 seconds (groundswell potential), the swell height is only 0.3 ft. That’s not even a ripple.
The Bottom Line
There’s nothing to chase here. For an area like this, a long blank run like this is pretty normal when the conditions don’t line up. It won’t stay this way forever, and forecasts can change, but for now, keep the board in the bag.
Rusty.
Short Range ForecastLight rain (total 6mm), mostly falling on Thu afternoon. Very mild (max 17°C on Thu afternoon, min 13°C on Tue night). Winds increasing (light winds from the WNW on Wed afternoon, strong winds from the SSW by Thu morning). | Days 5-7 Weather SummaryLight rain (total 3mm), mostly falling on Fri night. Very mild (max 17°C on Sat afternoon, min 13°C on Fri night). Winds decreasing (strong winds from the SSW on Sat morning, light winds from the WSW by Sun afternoon). | |||||||||||||||||||
Tue 8 | Wednesday 9 | Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | ||||||||||||||
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) | WNW 5 | SW 6 | SW 8 | SW 8 | SW 4 | SSW 5 | SW 7 | SW 7 | SW 7 | SW 7 | SSW 3 | SW 6 | SW 6 | SW 7 | SW 6 | SW 6 | SSW 6 | SSW 4 | SSW 4 | SW 6 |
Wave Graph  | ||||||||||||||||||||
 kJ | 109 | 10 | 15 | 14 | 21 | 130 | 400 | 158 | 38 | 22 | 10 | 284 | 188 | 100 | 39 | 17 | 12 | 25 | 12 | 138 |
Wind (km/h) | ||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross | cross | cross | cross-on | cross-on | cross-on | cross-on | cross | cross-on | cross-on | cross-on | on | cross-on | cross-off | on | cross-on | cross-on | on | on |
High Tide | 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 | 12:25PM5.56m | 00:40AM5.77m | 1:00PM5.44m | 1:15AM5.55m | |||||||
Low Tide | 3:33AM1.02m | 3:50PM1.24m | 4:19AM0.68m | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | 5:39AM0.42m | 5:49PM0.68m | 6:16AM0.50m | 6:26PM0.74m | 6:52AM0.70m | 7:02PM0.91m | ||||||||
 |  |  | | |  | |  |  | |  | | | | | | | | | | |
 | — | — | 6:39 | — | — | 6:41 | — | — | 6:43 | — | — | 6:45 | — | — | 6:47 | — | — | 6:48 | — | — |
 | 7:52 | — | — | 7:50 | — | — | 7:46 | — | — | 7:45 | — | — | 7:42 | — | — | 7:39 | — | — | 7:37 | — |
mm | 2 | — | — | — | — | 1 | 3 | — | — | — | 1 | 2 | — | — | — | — | — | — | — | — |
Temp °C | 16 | 14 | 13 | 14 | 15 | 16 | 17 | 17 | 14 | 15 | 14 | 16 | 17 | 17 | 14 | 15 | 16 | 17 | 17 | 18 |
Feels °C | 10 | 6 | 8 | 11 | 10 | 9 | 14 | 13 | 10 | 13 | 12 | 10 | 12 | 13 | 12 | 13 | 14 | 15 | 15 | 16 |
Swell 1 Height (m) Direction Period (s) | SW 10 | SW 6 | SW 8 | N 5 | N 4 | — | — | SW 7 | SW 7 | SW 7 | — | — | — | SW 7 | SW 6 | SW 6 | — | — | — | — |
| kJ | 4 | 10 | 15 | 28 | 1 | — | — | 158 | 38 | 22 | — | — | — | 100 | 39 | 17 | — | — | — | — |
Swell 2 Height (m) Direction Period (s) | — | SW 11 | SW 6 | SW 8 | — | — | — | — | — | NNW 4 | — | — | — | — | N 4 | N 4 | — | — | — | — |
| kJ | — | 4 | 5 | 14 | — | — | — | — | — | 6 | — | — | — | — | 2 | 1 | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | WNW 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | 2 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | WNW 5 | NW 6 | NNW 6 | W 4 | SW 4 | SSW 5 | SW 7 | — | NW 4 | WNW 4 | SSW 3 | SW 6 | SW 6 | — | — | — | SSW 6 | SSW 4 | SSW 4 | SW 6 |
| kJ | 109 | 224 | 131 | 3 | 21 | 130 | 400 | — | 14 | 2 | 10 | 284 | 188 | — | — | — | 12 | 25 | 12 | 138 |
Nearest Offshore or Glassy | ||||||||||||||||||||
Distance (km) | 548 | 346 | 187 | 51 | 238 | 312 | 514 | 174 | 179 | 51 | 179 | 246 | 299 | 88 | 51 | 155 | 238 | 186 | 251 | 192 |
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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