Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 2 Sep 2026:
- Most powerful swell: Wednesday 9 Sep, 4AM (local time) - 8ft (2.5m), 6s period, W swell with 567 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 2.5m 6s and forecast to arrive on Wednesday (Sep 09) at 4AM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.6m 6s period and expected on Wednesday (Sep 09) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4AM (Wed 9th Sep) | 8ft (2.5m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright mate, this is a grim one for Trearddur Bay (Holy Island). Over the next 16 days, there’s very little to get excited about. The wind is a mess, and the water is a touch warmer than usual for this time of year, sitting at 62°F, but that’s the only nice thing.
Wednesday the 2nd kicks off with light rain, a stiff 22 mph SSE breeze, and a weak, short-period 4ft swell from the SSW. The combined energy is a meager 96. It’s messy, lumpy, and just plain ugly. The afternoon is no better. Thursday the 3rd and Friday the 4th are the same story: onshore winds, mediocre swell, and poor conditions. On Friday the 4th, we get a 6ft swell from the WSW, but the 25 mph cross-on wind ruins it.
The weekend, the 5th and 6th, is tiny and blown out. The swell drops below 3ft, and the wind is still on it. It’s a proper lull. Monday the 7th shows a pulse of energy, with a 6ft SW swell hitting 258 in the afternoon, but again, the wind is onshore from the WSW. It’s powerful, but it’ll be a messy, choppy wall of water.
The best of a bad bunch looks like it might be the 8th and 9th of September. On Tuesday the 8th, we’ve got a 7ft swell from the WSW, with a combined energy of 333. That’s a solid push of power. But the wind is a strong 28 mph cross-on from the WSW, so it’s going to be a battle. The setup looks more interesting for kite surfing than paddle surfing. The wave period is only 6 seconds, so it’s a short-period windswell, which will be very lumpy. Wednesday the 9th is similar, with a 6ft NW swell and 339 energy, but the wind stays cross-on.
After that, it drops off a cliff. The second week is flat. On Thursday the 10th, we get a clean, cross-off wind from the NNE, but the swell is a pathetic 0.7ft. It’s a total dud. The 11th and 12th are tiny, and the 13th sees a return of some 6ft SSW swell, but the wind is cross-on, making it choppy.
The real kicker is that Trearddur Bay is exposed to the SW, which is the direction we’re seeing most of the swell from, but the wind is almost always wrong. It’s inconsistent at the best of times, and this forecast is a classic example of a blank run for this area. Don’t hold your breath; the forecasts can change, but right now, it’s a proper bleak stretch.
Rusty.
Short Range ForecastModerate rain (total 18mm), heaviest on Thu night. Very mild (max 18°C on Wed afternoon, min 13°C on Fri night). Mainly fresh winds. | Days 4-6 Weather SummaryLight rain (total 2mm), mostly falling on Mon afternoon. Warm (max 20°C on Sun afternoon, min 12°C on Mon afternoon). Winds increasing (light winds from the W on Sat morning, near gales from the SSW by Mon morning). | ||||||||||||||||||||
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 | SW 6 | SW 6 | WSW 5 | SW 5 | WNW 5 | SW 6 | SSW 3 | SSW 4 | S 4 | SSW 6 | SW 6 | SW 5 | SW 6 | WSW 6 | WSW 6 | WSW 6 | W 6 |
Wave Graph  | |||||||||||||||||||||
 kJ | 91 | 154 | 268 | 164 | 165 | 120 | 155 | 98 | 39 | 18 | 7 | 16 | 19 | 81 | 138 | 94 | 258 | 215 | 333 | 272 | 411 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | on | on | on | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on | cross-on | cross-on | cross-on |
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 | 6 | — | — | — | 1 | 11 | — | — | — | — | — | — | — | — | — | — | 2 | — | — | — | — |
Temp °C | 16 | 18 | 18 | 17 | 17 | 16 | 15 | 17 | 16 | 14 | 14 | 16 | 19 | 20 | 18 | 16 | 16 | 14 | 15 | 15 | 14 |
Feels °C | 11 | 14 | 13 | 13 | 12 | 11 | 8 | 11 | 10 | 11 | 10 | 11 | 11 | 15 | 13 | 7 | 8 | 4 | 7 | 7 | 6 |
Swell 1 Height (m) Direction Period (s) | S 16 | SW 16 | SW 15 | SW 14 | — | SW 6 | SW 14 | NW 6 | SW 5 | SW 6 | N 4 | SW 13 | SW 13 | SW 13 | SW 12 | SW 13 | — | — | — | — | — |
| kJ | 5 | 10 | 9 | 8 | — | 120 | 8 | 1 | 23 | 18 | 1 | 7 | 7 | 6 | 6 | 27 | — | — | — | — | — |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | NW 4 | — | SW 14 | SW 7 | NNW 4 | WNW 3 | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | 4 | — | 8 | 12 | 8 | 1 | — | — | — | — | — | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | SW 14 | — | — | SW 14 | SW 14 | NW 4 | — | — | — | — | — | — | — | — | — | — |
| kJ | — | — | — | — | — | 8 | — | — | 8 | 7 | 1 | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SSW 5 | SSW 6 | SW 7 | SW 7 | SW 6 | — | WSW 5 | SW 5 | WNW 5 | WNW 4 | SSW 3 | SSW 4 | S 4 | SSW 6 | SW 6 | SW 5 | SW 6 | WSW 6 | WSW 6 | WSW 6 | W 6 |
| kJ | 91 | 154 | 268 | 164 | 165 | — | 155 | 98 | 39 | 3 | 7 | 16 | 19 | 81 | 138 | 94 | 258 | 215 | 333 | 272 | 411 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 249 | 252 | 280 | 287 | 288 | 167 | 548 | 280 | 179 | 51 | 246 | 179 | 385 | 189 | 206 | 296 | 174 | 575 | 838 | 792 | 280 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
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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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