Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 1 Sep 2026:
- Most powerful swell: Tuesday 8 Sep, 4AM (local time) - 10ft (3.0m), 8s period, SW swell with 1,108 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 08) 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 0.4m 4s period and expected on Saturday (Sep 05) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4AM (Tue 8th Sep) | 10ft (3.0m) 8s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s talk about what’s happening at Trearddur Bay (Holy Island). I’ve got to be straight with you – this outlook is a tough one. The whole 16-day window is a write-off for decent surf. There are no good options on the cards, not a single session that’s worth paddling out for. It’s rare to see a blank run like this, but when the wind and swell just won’t line up, that’s the way it goes.
We start off on Tuesday, 1st September and it’s already a mess. Swell is tiny at 3 ft from the SW with a short, weak period of 4 seconds, and the wind is howling onshore at 16 mph. Combined energy is a pathetic 21 – barely a ripple. It’s poor, and it stays poor. Wednesday the 2nd sees a bump in height to 6 ft, but with a fresh cross-shore wind at 19 mph, it’s lumpy, choppy, and ugly. The energy climbs to 173 (moderate), but the quality is just not there.
The whole first week is a blur of onshore and cross-onshore winds, with swell heights bouncing between 1 ft and 5 ft. Thursday the 3rd, Friday the 4th, Saturday the 5th – all poor. On Sunday the 6th, we get a bit of push with 5 ft from the SSW and 160 energy, but a fresh cross-onshore wind at 22 mph ruins it. Nothing to get excited about.
Then things get weird. On Monday the 7th, the swell drops right back to 2 ft and 3 ft with light winds, but it’s still too small and weak. Then Tuesday the 8th brings a sudden spike – 8 ft from the WSW with a near gale force wind of 31 mph. The energy jumps to 418 (strong), but that’s a full-on stormy mess. That’s expert-only, big and blown out. For the average surfer, it’s a kite day, not a paddle day.
After that, the wind stays strong and cross-onshore through Wednesday the 9th, with 4 ft from the NW and 120 energy, but it’s messy. Thursday the 10th and Friday the 11th finally see clean, glassy conditions with light offshore or cross-offshore breezes, but the swell is gone – just 2 ft and 0.3 ft. The combined energy is 18 or less. It’s pretty, but there’s nothing to ride.
Saturday the 12th is the same story: glassy conditions, but only 0.7 ft of swell. You’d be floating. Sunday the 13th brings a bump to 6 ft from the SSW with 194 energy, but it’s cross-shore and messy. By Monday the 14th, we finally get a bit of hope: a glassy calm morning with 4 ft from the WSW, clean conditions, and a combined energy of 66. The forecast says “surfable waves but very ordinary conditions” – that’s the best we get, and it’s a 1 out of 10. It’s not good, but it’s the only thing that’s even surfable.
The last two days, Tuesday the 15th and Wednesday the 16th, are back to poor – cross-onshore winds, lumpy, choppy. No standouts, no hidden gems. If you’re desperate, Monday the 14th morning is your only shot, but keep expectations low.
Look, the water temperature is 62°F with a 1°F anomaly, so a touch warmer than normal for this time of year, but that’s about the only positive here. The waves just aren’t cooperating. Stay patient – forecasts can change, and it won’t stay this poor forever.
Rusty.
Short Range ForecastModerate rain (total 18mm), heaviest on Wed morning. Very mild (max 18°C on Tue night, min 15°C on Tue morning). Winds increasing (light winds from the SW on Tue night, near gales from the SSW by Thu night). | Days 4-6 Weather SummaryMostly dry. Very mild (max 17°C on Fri afternoon, min 13°C on Fri night). Mainly fresh winds. | ||||||||||||||||||||
Tuesday 1 | Wednesday 2 | Thursday 3 | Friday 4 | Saturday 5 | Sunday 6 | Monday 7 | |||||||||||||||
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 4 | SSW 5 | SW 5 | SSW 6 | SSW 6 | SW 7 | SW 7 | SW 5 | SW 7 | SSW 7 | SW 4 | NW 5 | NW 5 | SSW 6 | SSW 3 | SSW 5 | SSW 6 | SSW 6 | SSW 6 | SSW 4 | SW 7 |
Wave Graph | |||||||||||||||||||||
21 | 87 | 41 | 173 | 196 | 244 | 85 | 57 | 255 | 78 | 42 | 59 | 21 | 12 | 7 | 62 | 160 | 170 | 25 | 28 | 561 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | on | cross | cross-on | on | on | cross-on | on | cross-on | cross-on | cross | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on |
High Tide | 1:36PM5.36m | 1:53AM5.56m | 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 | ||||||||
Low Tide | 7:42PM1.01m | 8:06AM0.98m | 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 | ||||||||
6:26 | — | — | 6:28 | — | — | 6:30 | — | — | 6:31 | — | — | 6:33 | — | — | 6:35 | — | — | 6:37 | — | — | |
— | 8:08 | — | — | 8:06 | — | — | 8:04 | — | — | 8:01 | — | — | 7:59 | — | — | 7:57 | — | — | 7:53 | — | |
mm | — | 1 | 2 | 10 | — | — | — | — | 5 | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 17 | 18 | 16 | 17 | 18 | 17 | 17 | 17 | 15 | 17 | 15 | 14 | 15 | 14 | 15 | 17 | 17 | 18 | 18 | 17 |
Feels °C | 11 | 12 | 16 | 11 | 13 | 15 | 13 | 13 | 11 | 9 | 11 | 9 | 10 | 11 | 10 | 9 | 12 | 12 | 16 | 16 | 16 |
Swell 1 Height (m) Direction Period (s) | — | — | SW 5 | — | SW 16 | SW 15 | WNW 4 | SW 14 | SSW 7 | SSW 7 | SW 14 | SW 6 | SW 6 | NNW 4 | SW 13 | SW 13 | — | SW 12 | SSW 6 | NW 4 | — |
— | — | 41 | — | 10 | 9 | 1 | 8 | 170 | 78 | 8 | 18 | 8 | 3 | 7 | 7 | — | 6 | 25 | 2 | — | |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | — | — | SW 14 | — | NW 4 | SW 14 | SW 14 | SW 14 | SW 14 | WNW 3 | — | — | — | — | SW 13 | N 4 | — |
— | — | — | — | — | — | 8 | — | 2 | 8 | 8 | 8 | 7 | 1 | — | — | — | — | 6 | 1 | — | |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | SW 14 | — | — | — | SW 14 | SW 13 | — | — | — | — | — | SW 12 | — |
— | — | — | — | — | — | — | — | 8 | — | — | — | 7 | 7 | — | — | — | — | — | 6 | — | |
Wind waves Height (m) Direction Period (s) | SW 4 | SSW 5 | — | SSW 6 | SSW 6 | SW 7 | SW 7 | SW 5 | SW 7 | WNW 4 | SW 4 | NW 5 | NW 5 | SSW 6 | SSW 3 | SSW 5 | SSW 6 | SSW 6 | NW 4 | SSW 4 | SW 7 |
21 | 87 | — | 173 | 196 | 244 | 85 | 57 | 255 | 20 | 42 | 59 | 21 | 12 | 7 | 62 | 160 | 170 | 19 | 28 | 561 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 305 | 292 | 246 | 249 | 246 | 284 | 285 | 251 | 251 | 179 | 51 | 179 | 178 | 236 | 163 | 189 | 297 | 292 | 280 | 285 | 246 |
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.











