Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 25 Aug 2026:
- Most powerful swell: Tuesday 1 Sep, 4PM (local time) - 10ft (3.0m), 8s period, SSW swell with 1,051 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 3.0m 8s and forecast to arrive on Tuesday (Sep 01) at 4PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.3m 4s period and expected on Saturday (Aug 29) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Tue 1st Sep) | 10ft (3.0m) 8s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Right then, let’s have a look at what’s cookin’ for Trearddur Bay over the next couple of weeks.
I’ll be straight with you, mate – it’s a tough outlook. The whole 16-day window is a battle with the wind. For the first few days, from Tuesday the 25th of August through to the 31st of August, the surf is just too small to bother with. We’re talking knee-high dribble at best, with the biggest push being a weak 4ft on the Friday morning, but it’s onshore and messy. You’d be better off doing something else. The water’s a touch warmer than normal for this time of year, sitting at 63°F, but that’s about the only bright spot.
We finally get a proper pulse of energy on the 1st of September, with a big SSW swell pushing through. The combined energy hits a massive 1051 (moderate to strong wave energy) on the Tuesday afternoon, with waves climbing to 10ft. But here’s the heartbreaker – the wind is howling onshore at 34 mph from the same direction as the swell. That’s a near-gale, and it’s gonna be a complete mess. With that size and that wind, this spot is frankly more interesting for kite surfing than paddle surfing. This is strictly for the experts only, and even then, it’ll be a battle.
The wind eases a little through the rest of the first week of September, but it’s never truly clean. We see a couple of pulses – a 6ft to 6ft SW swell on the 5th of September with moderate energy (around 354 to 396) but the wind is cross-shore and lumpy, so it’s not going to be pretty. The following morning, the 6th, has a 7ft WSW swell, but again, it’s blown out by strong onshore winds.
Look, there’s no standout winner here. The only real window of possibility is the 5th of September. If you’re desperate, the Saturday morning has a 6ft SW swell with a fair bit of energy (354), and while the wind is a fresh cross-onshore, it’s the least offensive of a bad bunch. It’s still going to be lumpy and choppy, and crowds are possible. But honestly, I’d be keeping the board in the car and checking the forecast again. This one’s a write-off for clean, quality waves.
Rusty.
Short Range ForecastModerate rain (total 11mm), heaviest on Thu morning. Warm (max 21°C on Wed afternoon, min 16°C on Tue morning). Winds decreasing (fresh winds from the E on Tue night, light winds from the SSE by Thu afternoon). | Days 4-6 Weather SummaryHeavy rain (total 24mm), heaviest during Sun morning. Very mild (max 17°C on Fri afternoon, min 13°C on Sun night). Winds increasing (light winds from the W on Sat night, strong winds from the W by Sun night). | ||||||||||||||||||||
Tuesday 25 | Wednesday 26 | Thursday 27 | Friday 28 | Saturday 29 | Sunday 30 | Monday 31 | |||||||||||||||
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) | SW 13 | SW 13 | SSW 8 | SW 8 | SSW 8 | SSW 7 | SSW 7 | SW 7 | SSW 4 | SSW 8 | SSW 7 | SSW 7 | SSW 6 | SSW 8 | SW 8 | SW 8 | SSW 8 | SSW 7 | SSW 7 | WSW 4 | SW 5 |
Wave Graph  | |||||||||||||||||||||
 kJ | 7 | 7 | 7 | 17 | 12 | 5 | 6 | 2 | 17 | 202 | 86 | 30 | 55 | 158 | 142 | 72 | 51 | 40 | 34 | 30 | 49 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-off | off | cross-off | cross-off | cross-off | cross-off | cross-off | cross | cross-on | on | on | cross-on | cross-on | cross-on | cross-on | cross-on | on | cross-on | cross-on | cross-on | on |
High Tide | 9:59PM5.08m | 10:26AM4.89m | 10:33PM5.32m | 10:57AM5.08m | 11:04PM5.51m | 11:27AM5.23m | 11:36PM5.65m | 11:57AM5.33m | 00:07AM5.72m | 12:28PM5.40m | 00:40AM5.74m | 1:01PM5.41m | 1:15AM5.69m | ||||||||
Low Tide | 3:46PM1.80m | 4:11AM1.47m | 4:21PM1.52m | 4:43AM1.19m | 4:52PM1.28m | 5:14AM0.96m | 5:23PM1.07m | 5:44AM0.80m | 5:55PM0.94m | 6:16AM0.70m | 6:28PM0.87m | 6:50AM0.69m | 7:04PM0.89m | ||||||||
 | |  |  |  |  |  | |  | | | | |  | | |  |  | | |  | |
 | 6:13 | — | — | 6:16 | — | — | 6:18 | — | — | 6:20 | — | — | 6:20 | — | — | 6:22 | — | — | 6:24 | — | — |
 | — | 8:24 | — | — | 8:22 | — | — | 8:20 | — | — | 8:17 | — | — | 8:15 | — | — | 8:13 | — | — | 8:10 | — |
mm | — | — | — | — | 2 | 1 | 6 | 2 | — | — | — | 5 | 2 | — | — | 8 | 4 | 5 | — | — | — |
Temp °C | 19 | 20 | 20 | 19 | 21 | 21 | 17 | 17 | 16 | 16 | 17 | 17 | 16 | 17 | 17 | 17 | 16 | 15 | 15 | 18 | 17 |
Feels °C | 17 | 18 | 13 | 19 | 20 | 20 | 16 | 18 | 14 | 12 | 16 | 14 | 14 | 15 | 16 | 12 | 10 | 8 | 8 | 14 | 13 |
Swell 1 Height (m) Direction Period (s) | SW 13 | — | SSW 8 | NE 5 | SSW 8 | SSW 7 | NE 4 | NNE 4 | — | — | SSW 7 | SSW 7 | SSW 6 | SSW 8 | SW 8 | SW 8 | SSW 8 | SSW 7 | SSW 7 | NW 4 | — |
| kJ | 7 | — | 7 | 4 | 12 | 5 | 3 | 2 | — | — | 86 | 30 | 55 | 158 | 142 | 72 | 51 | 40 | 34 | 6 | — |
Swell 2 Height (m) Direction Period (s) | SW 8 | SW 13 | S 13 | SW 8 | NE 5 | S 12 | SSW 7 | SW 7 | — | — | — | S 11 | NNW 5 | — | — | NW 4 | WNW 3 | — | SW 10 | SSW 10 | — |
| kJ | 3 | 7 | 3 | 17 | 3 | 3 | 5 | 2 | — | — | — | 2 | 2 | — | — | 8 | 1 | — | 4 | 10 | — |
Swell 3 Height (m) Direction Period (s) | — | SW 8 | S 13 | SSE 4 | — | — | SW 12 | — | — | — | — | — | — | — | — | — | N 4 | — | — | — | — |
| kJ | — | 3 | 3 | 2 | — | — | 6 | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — |
Wind waves Height (m) Direction Period (s) | E 3 | NE 5 | ENE 4 | — | — | — | — | — | SSW 4 | SSW 8 | WNW 3 | WNW 3 | — | NW 5 | WNW 4 | SW 5 | — | NNE 3 | WNW 4 | WSW 4 | SW 5 |
| kJ | 4 | 6 | 19 | — | — | — | — | — | 17 | 202 | 4 | 4 | — | 63 | 19 | 15 | — | 1 | 15 | 30 | 49 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 252 | 249 | 189 | 316 | 303 | 275 | 249 | 249 | 186 | 101 | 284 | 280 | 167 | 51 | 8 | 246 | 251 | 565 | 556 | 514 | 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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