
Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 3 Aug 2026:
- Most powerful swell: Wednesday 5 Aug, 1PM (local time) - 7ft (2.1m), 6s period, WSW swell with 310 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 2.1m 6s and forecast to arrive on Wednesday (Aug 05) at 1PM. Winds are predicted to be cross-onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 0.7m 6s period and expected on Thursday (Aug 06) at 1PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 1PM (Wed 5th Aug) | 7ft (2.1m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here. Let’s talk about Trearddur Bay.
Honestly, the next 16 days are a real bummer. There’s a dead zone stretching from Monday, August 3rd, all the way to the morning of Sunday, August 16th. That’s nearly two weeks of flat, messy conditions with no surf worth a mention. The swell is tiny, the wind is all over the place, and the wave comment is “poor surf conditions” for every single day in that stretch.
The only break in the dry spell is Sunday, August 16th. Trearddur Bay (Holy Island) finally wakes up a little. The morning brings a 1.4m swell from the NW, with a short period of 5 seconds. The wind is glassy – dead calm, not a breath – so the surface will be smooth as glass. Combined energy is moderate at 120. The afternoon is similar: 1.4m from the NW, still 5 seconds, but the wind turns to a light cross-offshore from the NNW, keeping it clean. Energy edges up to 139. It’s not epic, but it’s surfable, and that glassy morning is a rare gem for this spot. The water is a touch warmer than normal at 17°.
That’s your only real shot. Monday, August 17th, goes glassy again but with zero swell—just a flat, calm sea. The rest of the forecast is a total washout.
If you’re a beginner, that 1.4m on the 16th is fine, but this spot is inconsistent and can get crowded sometimes. For the rest of the 16 days, you’re better off kicking back and waiting for the next system to roll in. It can’t stay this poor forever.
Rusty.
Short Range ForecastLight rain (total 5mm), mostly falling on Mon night. Warm (max 21°C on Mon morning, min 14°C on Tue night). Winds increasing (calm on Mon night, strong winds from the W by Wed afternoon). | Days 4-6 Weather SummaryMostly dry. Very mild (max 17°C on Sat afternoon, min 13°C on Thu morning). Winds decreasing (fresh winds from the SSW on Fri afternoon, light winds from the W by Sat night). | ||||||||||||||||||||
Monday 3 | Tuesday 4 | Wednesday 5 | Thursday 6 | Friday 7 | Saturday 8 | Sunday 9 | |||||||||||||||
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) | SSE 4 | SW 8 | SW 8 | SSW 5 | SSW 5 | SSW 6 | WSW 6 | WSW 6 | WNW 6 | NW 5 | SW 6 | SW 5 | SW 5 | SSW 4 | SW 6 | SW 5 | SW 6 | SW 6 | W 4 | SW 5 | SW 4 |
Wave Graph | |||||||||||||||||||||
3 | 11 | 11 | 64 | 74 | 112 | 215 | 246 | 240 | 71 | 16 | 7 | 12 | 18 | 107 | 100 | 151 | 38 | 11 | 7 | 5 | |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | cross-on | cross-off | cross-on | cross-on | on | cross-on | cross-on | cross-on | cross | on | cross-on | on | cross-on | on | on | on | cross | cross | cross | off |
High Tide | 2:07PM5.09m | 2:20AM5.40m | 2:46PM5.01m | 3:02AM5.25m | 3:31PM4.87m | 3:52AM5.04m | 4:26PM4.70m | 4:55AM4.80m | 5:37PM4.56m | 6:16AM4.64m | 7:05PM4.57m | 7:47AM4.68m | 8:27PM4.80m | ||||||||
Low Tide | 8:09PM1.21m | 8:35AM1.03m | 8:51PM1.35m | 9:20AM1.21m | 9:40PM1.55m | 10:13AM1.46m | 10:41PM1.77m | 11:18AM1.72m | 11:58PM1.91m | 12:38PM1.85m | 1:25AM1.83m | 1:59PM1.77m | 2:41AM1.51m | ||||||||
5:37 | — | — | 5:37 | — | — | 5:39 | — | — | 5:41 | — | — | 5:43 | — | — | 5:45 | — | — | 5:47 | — | — | |
— | — | 9:10 | — | — | 9:08 | — | — | 9:07 | — | — | 9:05 | — | — | 9:02 | — | — | 9:00 | — | 8:59 | — | |
mm | — | — | 4 | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 21 | 19 | 17 | 17 | 18 | 17 | 16 | 16 | 15 | 14 | 15 | 16 | 15 | 16 | 16 | 15 | 17 | 17 | 15 | 18 | 17 |
Feels °C | 20 | 17 | 17 | 14 | 13 | 12 | 8 | 9 | 8 | 10 | 12 | 12 | 11 | 11 | 11 | 10 | 14 | 16 | 13 | 18 | 15 |
Swell 1 Height (m) Direction Period (s) | NE 4 | S 4 | SW 8 | SW 8 | — | — | — | — | S 13 | SW 6 | N 5 | SW 5 | NW 4 | S 12 | — | SW 11 | S 11 | SW 6 | SW 8 | NW 4 | SW 4 |
3 | 2 | 11 | 10 | — | — | — | — | 3 | 29 | 20 | 7 | 2 | 3 | — | 5 | 2 | 38 | 2 | 3 | 4 | |
Swell 2 Height (m) Direction Period (s) | SW 9 | SW 8 | — | NE 4 | — | — | — | — | — | S 13 | WNW 4 | N 4 | SW 12 | SW 12 | — | — | — | S 11 | — | SW 7 | SSW 7 |
3 | 11 | — | 1 | — | — | — | — | — | 3 | 7 | 2 | 6 | 6 | — | — | — | 2 | — | 2 | 5 | |
Swell 3 Height (m) Direction Period (s) | — | NE 4 | — | — | — | — | — | — | — | — | S 12 | SW 12 | — | — | — | — | — | — | S 12 | SW 12 | S 12 |
— | 1 | — | — | — | — | — | — | — | — | 3 | 6 | — | — | — | — | — | — | 3 | 6 | 3 | |
Wind waves Height (m) Direction Period (s) | SSE 4 | — | SSW 4 | SSW 5 | SSW 5 | SSW 6 | WSW 6 | WSW 6 | WNW 6 | NW 5 | SW 6 | WNW 3 | SW 5 | SSW 4 | SW 6 | SW 5 | SW 6 | WNW 3 | W 4 | SW 5 | NNW 2 |
2 | — | 3 | 64 | 74 | 112 | 215 | 246 | 240 | 71 | 16 | 1 | 12 | 18 | 107 | 100 | 151 | 4 | 11 | 7 | 1 | |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 155 | 155 | 155 | 280 | 283 | 278 | 246 | 1083 | 179 | 284 | 273 | 273 | 246 | 251 | 219 | 358 | 376 | 51 | 163 | 323 | 235 |
Best forecast wave conditions in Anglesy | |||||||||||||||||||||
Best forecast wave conditions in United Kingdom | |||||||||||||||||||||
Header Global | |||||||||||||||||||||
- Map Icons:
Break
Live Wave Height (m)
Live Wind Speed (km/h)
Surf Rating (10 Max)
Ocean Swells (m)
Wind Speed (km/h)
Latest Updates
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.











