Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 10 Sep 2026:
- Best quality surf: Saturday 12 Sep, 10PM (local time) - 4.5ft (1.4m), 7s period, SW swell with cross-offshore winds.
- Most powerful swell: Saturday 12 Sep, 1PM (local time) - 7ft (2.2m), 7s period, SW swell with 447 kJ wave energy.
- Next surfable swell (1★+): Saturday 12 Sep, 10PM (local time) - 4.5ft (1.4m), 7s period with SW swell.
Best Forecast Surf Conditions for Trearddur Bay (Holy Island) this week:
The surf forecast for Trearddur Bay (Holy Island) over the next 16 days: The first swell (rated 1 star or higher) is forecast to arrive on Saturday (Sep 12) at 10PM. The primary swell is predicted to be 1.4m and 7s period. The wind is predicted to be cross-offshore as the swell arrives.
The most powerful waves expected at Trearddur Bay (Holy Island) in the next 16 days are 2.2m 7s and forecast to arrive on Saturday (Sep 12) at 1PM. Winds are predicted to be onshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.4m 5s period and expected on Tuesday (Sep 15) at 10PM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | 10PM (Sat 12th Sep) | 4.5ft (1.4m) 7s |
| Best Surf | 10PM (Sat 12th Sep) | 4.5ft (1.4m) 7s |
| Most Powerful | 1PM (Sat 12th Sep) | 7ft (2.2m) 7s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright folks, Rusty here. Let’s have a look at what’s cookin’ for the next couple of weeks around Trearddur Bay on Holy Island.
Right off the bat, I gotta be straight with you – it’s a grim outlook. We’ve got a solid gap of nothing worthwhile for the first ten days. From now until late on the 19th of September, it’s just one poor session after another. Strong winds, messy cross-onshore slop, and tiny or messy swell. Not a single window worth paddling out for.
We finally get a little flicker of hope on the morning of Sunday the 20th of September. That’s the one standout in this whole 16-day run. The swell fills in a bit from the WNW at 4ft, with a moderate wave energy rating (112). The wind is a light breeze from the NW, which is cross-offshore, cleaning things right up. Conditions will be clean, and for a spot that’s fairly exposed to SW swell, getting a clean, lined-up WNW pulse with light offshores is a rare treat. The water temp is about average for this time of year, so you won’t need a thick hood unless you run cold. Keep in mind Trearddur Bay is a beginner spot and it’s inconsistent, so don’t expect a pumping machine – but for a Sunday morning session, this is as good as it’s gonna get. Crowds are possible here, so get in early if you want it to yourself. The swell period is a short 6 seconds, so it’ll be a bit weaker and mushier than a proper groundswell, but clean waves are clean waves. After that morning, the surf drops off again into tiny, weak dribble for the rest of the period.
The setup here is a beach, so with the strong winds and poor surf quality that dominate the forecast, honestly, most of this window looks more interesting for kite surfing than paddle surfing. Unless you’re desperate, I’d give it a miss until that Sunday morning.
Stay patient, lads. It’ll turn around eventually.
Rusty.
Short Range ForecastLight rain (total 7mm), mostly falling on Sat morning. Very mild (max 18°C on Thu afternoon, min 13°C on Fri morning). Winds decreasing (strong winds from the SSW on Thu morning, light winds from the WSW by Fri afternoon). | Days 4-6 Weather SummaryModerate rain (total 13mm), heaviest on Tue morning. Very mild (max 18°C on Mon afternoon, min 13°C on Sun morning). Winds increasing (light winds from the NNE on Sat night, strong winds from the S by Mon night). | ||||||||||||||||||||
Thursday 10 | Friday 11 | Saturday 12 | Sunday 13 | Monday 14 | Tuesday 15 | Wednesday 16 | |||||||||||||||
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 7 | SW 7 | SW 7 | SW 6 | SSW 5 | SW 7 | SW 7 | SSW 6 | SW 6 | SW 6 | SSW 4 | SSW 6 | SSW 6 | SSW 7 | SW 6 | NW 5 | SSW 6 | SW 5 | W 3 | N 4 |
Wave Graph  | |||||||||||||||||||||
 kJ | 123 | 437 | 118 | 44 | 20 | 83 | 434 | 286 | 88 | 19 | 9 | 20 | 168 | 226 | 380 | 52 | 54 | 3 | 1 | 2 | 0 |
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 | on | on | cross-off | cross-off | on | cross-on | on | cross-on | cross-on | cross-on | cross | cross | cross-off | cross-off | cross |
High Tide | 10:36AM5.47m | 10:49PM5.85m | 11:14AM5.59m | 11:28PM5.95m | 11:50AM5.61m | 00:04AM5.91m | 12:25PM5.56m | 00:40AM5.77m | 1:00PM5.44m | 1:15AM5.55m | 1:34PM5.27m | 1:50AM5.26m | 2:09PM5.06m | 2:27AM4.94m | |||||||
Low Tide | 4:19AM0.68m | 4:32PM0.95m | 5:00AM0.47m | 5:11PM0.75m | 5:39AM0.42m | 5:49PM0.68m | 6:16AM0.50m | 6:26PM0.74m | 6:52AM0.70m | 7:02PM0.91m | 7:27AM0.99m | 7:38PM1.17m | 8:03AM1.34m | 8:16PM1.50m | |||||||
 | |  |  | |  | |  | | |  | | | | | |  | | | | | |
 | 6:41 | — | — | 6:43 | — | — | 6:45 | — | — | 6:47 | — | — | 6:48 | — | — | 6:50 | — | — | 6:52 | — | — |
 | — | 7:46 | — | — | 7:45 | — | — | 7:42 | — | — | 7:39 | — | — | 7:37 | — | — | 7:35 | — | — | 7:32 | — |
mm | 1 | 2 | — | — | — | 1 | 2 | 1 | 1 | — | — | — | — | — | — | 12 | — | 3 | 1 | — | — |
Temp °C | 15 | 18 | 18 | 13 | 14 | 16 | 17 | 18 | 16 | 13 | 14 | 15 | 17 | 18 | 17 | 17 | 17 | 15 | 14 | 14 | 14 |
Feels °C | 7 | 15 | 15 | 9 | 11 | 8 | 12 | 14 | 16 | 12 | 11 | 10 | 15 | 14 | 12 | 11 | 14 | 10 | 8 | 10 | 11 |
Swell 1 Height (m) Direction Period (s) | — | — | SW 7 | SW 7 | SW 6 | — | — | — | SSW 6 | SW 6 | N 4 | — | — | — | — | SW 6 | SW 6 | SSW 6 | SW 5 | NNW 4 | N 4 |
| kJ | — | — | 118 | 44 | 20 | — | — | — | 88 | 19 | 6 | — | — | — | — | 52 | 16 | 3 | 1 | 6 | 1 |
Swell 2 Height (m) Direction Period (s) | — | — | — | — | NNW 4 | — | — | — | — | — | SW 6 | S 13 | — | — | — | — | — | S 11 | — | W 3 | — |
| kJ | — | — | — | — | 3 | — | — | — | — | — | 9 | 3 | — | — | — | — | — | 2 | — | 2 | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | — | — | — | — | — | — | — | W 3 | — | — | — | — | — | — | — | — | SW 5 | — |
| kJ | — | — | — | — | — | — | — | — | — | — | 1 | — | — | — | — | — | — | — | — | 1 | — |
Wind waves Height (m) Direction Period (s) | SSW 5 | SSW 7 | WNW 4 | NW 4 | WNW 3 | SSW 5 | SW 7 | SW 7 | NW 4 | NNW 5 | — | SSW 4 | SSW 6 | SSW 6 | SSW 7 | NW 4 | NW 5 | NNW 6 | NNW 5 | WNW 3 | — |
| kJ | 123 | 437 | 11 | 12 | 2 | 83 | 434 | 286 | 13 | 37 | — | 20 | 168 | 226 | 380 | 27 | 54 | 111 | 36 | 2 | — |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 292 | 101 | 259 | 179 | 51 | 283 | 319 | 376 | 10 | 161 | 179 | 234 | 246 | 251 | 186 | 246 | 599 | 195 | 236 | 223 | 192 |
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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