Surf Forecasts:
Trearddur Bay (Holy Island) surf forecast from 9 Aug 2026:
- Most powerful swell: Monday 10 Aug, 10AM (local time) - 1.5ft (0.4m), 6s period, SW swell with 8 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 0.4m 6s and forecast to arrive on Monday (Aug 10) at 10AM. Winds are predicted to be cross-offshore at the time the swell arrives. The largest open ocean swell (not directed at the beach) is 1.0m 5s period and expected on Saturday (Aug 15) at 7AM.
| Wave Type | Time (BST) & Date | Wave Height & Period |
|---|---|---|
| Next good surf (1 star+) | - | - |
| Best Surf | - | - |
| Most Powerful | 10AM (Mon 10th Aug) | 1.5ft (0.4m) 6s |
Table - best surf conditions forecast for Trearddur Bay (Holy Island) over the next 16 days.
The Lowdown
Alright, Rusty here. Let's have a look at what's on the cards for Trearddur Bay.
Honestly, lads, it's a tough stretch ahead. The next few weeks are looking pretty flat for Trearddur Bay (Holy Island). We've got a long run of days with next to nothing, and the swell that does show up is tiny and poor. The first real bit of surf to get excited about doesn't arrive until Saturday the 22nd of August, and even then, it's a waiting game.
The whole first week and a half is a write-off. From the 9th through to the 21st, we're looking at waves that are basically flat, with heights barely reaching 2 ft and combined swell energy stuck below 20 (weak). The wind is messy, mostly onshore or cross-on, which just chops up the already tiny leftovers. There's nothing to ride here.
Now, the one bright spot in the whole forecast is the morning of Sunday the 23rd of August. That's the standout. We get a jump in swell to a proper 5 ft coming from the southwest, with a period of 6 seconds. The combined swell energy jumps to 157 (moderate), which is the only real energy we see in the whole window. The wind is a clean cross-off from the NNW, so the waves will be clean and lined up. This is the only day worth paddling out for. It's a small wave, not for the experts, but for a beginner-friendly spot like Trearddur Bay, that's a fun, clean little day. Just keep in mind, crowds are possible here.
After that, Monday the 24th sees the swell drop right back to nothing again.
So, bank everything on that Sunday the 23rd of August. It's a long wait, but it's the only chance for a decent session.
Rusty.
Short Range ForecastMostly dry. Warm (max 21°C on Tue afternoon, min 14°C on Sun night). Wind will be generally light. | Days 4-6 Weather SummaryMostly dry. Warm (max 25°C on Wed afternoon, min 16°C on Thu night). Wind will be generally light. | ||||||||||||||||||||
Sunday 9 | Monday 10 | Tuesday 11 | Wednesday 12 | Thursday 13 | Friday 14 | Saturday 15 | |||||||||||||||
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) | S 12 | SW 12 | SSW 4 | SW 6 | SW 6 | SSW 6 | SSW 6 | SW 6 | S 11 | SW 12 | S 12 | SW 9 | SW 10 | SW 11 | SW 11 | SW 6 | SW 6 | SW 6 | SW 6 | SW 6 | W 8 |
Wave Graph  | |||||||||||||||||||||
 kJ | 3 | 6 | 7 | 8 | 5 | 4 | 4 | 1 | 2 | 5 | 4 | 3 | 4 | 4 | 5 | 2 | 1 | 1 | 1 | 1 | 1 |
Wind (km/h) | |||||||||||||||||||||
Wind State on-shore cross-onshore cross-shore cross-offshore off-shore glassy | on | on | cross-off | cross-off | cross-off | off | cross-on | on | cross | cross-on | cross | cross-on | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | cross-off | off |
High Tide | 7:47AM4.68m | 8:27PM4.80m | 9:03AM4.91m | 9:30PM5.16m | 10:01AM5.19m | 10:21PM5.51m | 10:50AM5.42m | 11:07PM5.78m | 11:35AM5.56m | 11:49PM5.94m | 12:16PM5.58m | 00:30AM5.96m | 12:56PM5.52m | 1:10AM5.85m | |||||||
Low Tide | 1:59PM1.77m | 2:41AM1.51m | 3:06PM1.52m | 3:41AM1.10m | 4:01PM1.21m | 4:33AM0.72m | 4:48PM0.94m | 5:19AM0.45m | 5:32PM0.74m | 6:02AM0.32m | 6:14PM0.67m | 6:44AM0.35m | 6:54PM0.71m | ||||||||
 | |  | | | |  | |  | | | | | | |  | | | | | | |
 | 5:47 | — | — | 5:48 | — | — | 5:50 | — | — | 5:52 | — | — | 5:54 | — | — | 5:54 | — | — | 5:56 | — | — |
 | — | 8:59 | — | — | 8:57 | — | — | 8:54 | — | — | 8:52 | — | — | 8:51 | — | — | 8:49 | — | — | 8:46 | — |
mm | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — | — |
Temp °C | 16 | 17 | 15 | 14 | 15 | 17 | 20 | 21 | 21 | 22 | 25 | 25 | 22 | 23 | 21 | 17 | 19 | 18 | 19 | 19 | 18 |
Feels °C | 14 | 14 | 12 | 12 | 12 | 14 | 16 | 18 | 20 | 19 | 22 | 23 | 20 | 20 | 20 | 12 | 14 | 14 | 17 | 15 | 16 |
Swell 1 Height (m) Direction Period (s) | SW 6 | — | SSW 4 | SW 6 | N 4 | SSW 6 | SSW 6 | SW 6 | SSW 4 | SW 12 | SSW 4 | SW 4 | — | SW 8 | SW 7 | SW 6 | SW 6 | SW 6 | SW 6 | SW 6 | W 8 |
| kJ | 2 | — | 7 | 8 | 3 | 4 | 4 | 1 | 2 | 5 | 2 | 1 | — | 3 | 2 | 2 | 1 | 1 | 1 | 1 | 1 |
Swell 2 Height (m) Direction Period (s) | S 12 | SW 12 | — | WNW 4 | SW 6 | — | — | NE 4 | SW 6 | — | SW 10 | SW 9 | SW 8 | SW 11 | — | — | — | — | — | — | — |
| kJ | 3 | 6 | — | 2 | 5 | — | — | 1 | 1 | — | 4 | 3 | 3 | 4 | — | — | — | — | — | — | — |
Swell 3 Height (m) Direction Period (s) | — | — | — | S 10 | W 3 | — | — | — | S 11 | S 6 | S 12 | — | SW 10 | — | SW 11 | — | — | — | — | — | — |
| kJ | — | — | — | 2 | 1 | — | — | — | 2 | 1 | 3 | — | 4 | — | 5 | — | — | — | — | — | — |
Wind waves Height (m) Direction Period (s) | SW 3 | SSW 3 | NNW 3 | N 4 | NNW 4 | — | SSE 3 | S 3 | — | S 3 | — | — | — | — | N 3 | N 4 | N 4 | N 4 | N 5 | N 5 | N 5 |
| kJ | 2 | 3 | 3 | 5 | 3 | — | 1 | 1 | — | 3 | — | — | — | — | 1 | 12 | 5 | 6 | 42 | 21 | 23 |
Nearest Offshore or Glassy | |||||||||||||||||||||
Distance (km) | 322 | 548 | 278 | 251 | 275 | 246 | 286 | 306 | 163 | 155 | 163 | 155 | 179 | 292 | 179 | 192 | 318 | 189 | 275 | 298 | 241 |
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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