Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 5 Sep 2026:
- Most powerful swell: Monday 7 Sep, 4PM (local time) - 7ft (2.1m), 6s period, SW swell with 320 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 Monday (Sep 07) 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 1.2m 5s period and expected on Saturday (Sep 12) at 7AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 4PM (Mon 7th Sep) | 7ft (2.1m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
G’day, Rusty here. Look, I’ve looked hard at the charts for Trearddur Bay (Holy Island) and I’ve got to be straight with you – the next 16 days are a tough watch. There’s not a single recommendation in the whole run. Let’s talk about why.
The first week is a mess of strong onshore and cross-onshore winds, mostly from the south and west, with fresh to strong breezes up to 25 mph. The swell is there, but it’s either short-period windswell or just poorly aligned. Saturday the 5th sees a 3ft W swell with a 5-second period, but it’s cross-on and choppy – energy is weak at 70. Sunday the 6th has a bit more size, 4ft to 5ft from the SSW, but with 22-25 mph cross-on winds, it’s just messy and lumpy. Monday the 7th afternoon gets up to 7ft from the SW, but again, onshore and blown out. The combined energy on Monday afternoon hits 320, which is moderate, but without clean wind, it’s a wasted push. Water temp is sitting around 63°F, which is a touch warmer than normal for this time of year, not that you’d want to be out in it.
The second week fades badly. From Tuesday the 10th through to the 20th, the swell drops to nothing – we’re talking 0.3ft to 1ft, with combined energy mostly under 10. The wind does go offshore from the north and northeast from the 17th onwards, which is clean, but there’s simply no swell to ride. A few specs of 0.3ft with a 14-second period show up on the 20th, but that’s groundswell with no height to speak of.
Honestly, there’s no standout day, no break to highlight, no best option. This is a proper blank run. For Trearddur Bay, it’s a beach-and-reef setup, and with this much wind and poor quality, you’d be better off looking at kite surfing setups if you’re desperate. Otherwise, save the petrol. Forecasts can change, but right now, it’s a no-go.
Rusty.
Short Range ForecastLight rain (total 8mm), mostly falling on Sat night. Very mild (max 19°C on Sun afternoon, min 13°C on Mon night). Winds increasing (light winds from the SW on Sat morning, strong winds from the SW by Mon afternoon). | Days 4-6 Weather SummaryLight rain (total 9mm), mostly falling on Wed night. Very mild (max 17°C on Thu morning, min 13°C on Tue night). Winds increasing (moderate winds from the W on Wed morning, strong winds from the SSW by Wed night). | ||||||||||||||||||||
Saturday 5 | Sunday 6 | Monday 7 | Tuesday 8 | Wednesday 9 | Thursday 10 | Friday 11 | |||||||||||||||
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) | W 5 | SW 6 | SSW 4 | SSW 5 | SSW 6 | SW 6 | SW 14 | SW 6 | SW 6 | WSW 6 | W 6 | NW 6 | SW 6 | WSW 4 | SW 4 | SW 6 | SW 7 | WSW 4 | WNW 6 | WNW 6 | NW 5 |
Wave Graph  | |||||||||||||||||||||
 kJ | 49 | 16 | 35 | 88 | 134 | 147 | 52 | 320 | 275 | 263 | 144 | 123 | 11 | 8 | 12 | 231 | 127 | 62 | 161 | 148 | 96 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | cross-on | on | cross-on | cross-on | cross-on | cross-on | on | on | cross-on | cross-on | cross-on | cross | cross | on | on | on | on | cross-on | cross | cross-on | cross |
High Tide | 5:21PM4.55m | 6:18AM4.51m | 7:01PM4.59m | 7:54AM4.65m | 8:23PM4.91m | 9:02AM4.96m | 9:21PM5.29m | 9:53AM5.26m | 10:08PM5.63m | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | ||||||||
Low Tide | 10:59AM2.01m | 11:50PM1.99m | 12:31PM2.14m | 1:25AM1.84m | 1:57PM1.96m | 2:38AM1.44m | 3:00PM1.61m | 3:33AM1.02m | 3:50PM1.24m | 4:19AM0.68m | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | ||||||||
 |  |  |  | |  | |  | | | |  | | | | | | |  | | | |
 | 6:33 | — | — | 6:35 | — | — | 6:37 | — | — | 6:39 | — | — | 6:39 | — | — | 6:41 | — | — | 6:43 | — | — |
 | — | 7:59 | — | — | 7:57 | — | — | 7:53 | — | — | 7:52 | — | — | 7:50 | — | — | 7:46 | — | — | 7:45 | — |
mm | — | — | 2 | 2 | — | 1 | — | 2 | 1 | — | — | — | — | — | 8 | — | 1 | — | — | — | — |
Temp °C | 14 | 15 | 15 | 18 | 19 | 17 | 15 | 16 | 15 | 14 | 16 | 14 | 14 | 15 | 16 | 17 | 17 | 16 | 15 | 16 | 15 |
Feels °C | 11 | 11 | 10 | 11 | 13 | 13 | 9 | 9 | 9 | 6 | 9 | 7 | 10 | 9 | 9 | 11 | 12 | 9 | 7 | 10 | 9 |
Swell 1 Height (m) Direction Period (s) | SW 7 | WNW 4 | SW 13 | SW 13 | SW 13 | SW 12 | SW 14 | — | — | — | SW 11 | SW 6 | SW 6 | N 5 | N 4 | — | — | — | SW 6 | — | SW 6 |
| kJ | 7 | 3 | 7 | 7 | 6 | 6 | 52 | — | — | — | 5 | 26 | 11 | 17 | 1 | — | — | — | 40 | — | 16 |
Swell 2 Height (m) Direction Period (s) | SW 14 | NNW 5 | — | — | — | — | NW 4 | — | — | — | W 10 | S 11 | — | — | SW 8 | — | — | — | — | — | SW 8 |
| kJ | 7 | 5 | — | — | — | — | 2 | — | — | — | 2 | 2 | — | — | 3 | — | — | — | — | — | 9 |
Swell 3 Height (m) Direction Period (s) | SW 14 | NW 4 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
| kJ | 7 | 1 | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | W 5 | SW 6 | SSW 4 | SSW 5 | SSW 6 | SW 6 | SW 4 | SW 6 | SW 6 | WSW 6 | W 6 | NW 6 | NW 5 | WSW 4 | SW 4 | SW 6 | SW 7 | WSW 4 | WNW 6 | WNW 6 | NW 5 |
| kJ | 49 | 16 | 35 | 88 | 134 | 147 | 52 | 320 | 275 | 263 | 144 | 123 | 58 | 8 | 12 | 231 | 127 | 62 | 161 | 148 | 96 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 51 | 235 | 186 | 312 | 347 | 219 | 315 | 548 | 174 | 280 | 548 | 179 | 284 | 235 | 246 | 280 | 302 | 280 | 548 | 548 | 179 |
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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